The Mathematics Curriculum Standard points out that effective mathematics activities can not only rely on imitation and memory, but also practice, independent exploration and cooperative communication are important ways for students to learn mathematics. I have been trying, exploring and summarizing in teaching, and students have basically formed a new way of learning, which has promoted their all-round and sustainable development, cultivated their lifelong learning ability and achieved the goal of curriculum reform. The concept of mathematics is a high generalization of the essential attributes of the research object in concise language, and it is the basis for students to learn mathematics and accept new knowledge. Accurately and thoroughly understanding and mastering the concepts in mathematics classroom learning is a necessary condition for students to learn mathematics well. Mathematical concepts generally include definitions, theorems and inferences, in which every word, sentence and comment have been carefully scrutinized and have specific meanings to ensure the integrity and scientificity of the concepts. The teaching of junior high school mathematics concepts plays a very important role in the whole teaching stage and even the whole mathematics learning. In addition, junior high school students' comprehension ability and reading ability are weak. Therefore, teachers should explain the concepts carefully in the teaching process and not ignore every concept. They should not think that concepts are rules, as long as students remember them, but let students understand and remember them thoroughly on this basis. This will not only make students firmly remember, but more importantly, students can learn from others through concepts, thus meeting the teaching requirements. Therefore, it is very important and necessary to teach junior high school mathematics concepts well. First, situational guidance, the concept of discovering essence is a summary of the essential attributes of the research object. The process of generalization of essential attributes is a thinking process from perceptual to rational, from special to general. In order to make students get a clear concept, it is necessary to fully implement such a process in concept teaching. According to the age characteristics of junior high school students, try to introduce concepts in combination with students' actual life experience, so that students can influence concepts subtly instead of memorizing words and phrases. For example, when teaching the concept of rectangular coordinates of points in the plane, it is essentially based on the one-to-one correspondence between points in the plane and ordered real number pairs. We can introduce the topic with some familiar examples such as students watching movies and finding seats, so that students can learn new concepts unconsciously instead of memorizing concepts. Of course, it should be noted that this is not an end in itself, but a means to achieve the teaching goal, in order to explore the abstract essential attributes of the research object with vivid examples, so we should focus on how to raise perceptual knowledge to rational knowledge. In addition, examples in life are not equal to mathematical concepts, some contain non-essential attributes, and some omit some essential attributes, so teachers must be practical when giving examples to prevent students from misinterpreting concepts and going to the other extreme. In addition, in the process of concept teaching, concepts should be formed in the system of concepts, not suddenly instilled in students. Starting from the introduction of original concepts, we should not only pay attention to introducing new concepts on the basis of students' existing knowledge, but also fully reveal the contradiction between new knowledge and old concepts, so that students can realize the limitations of old concepts and the necessity of learning new concepts. This requires our teachers to analyze the position of new concepts in the concept system well before teaching. For example, the position of the arithmetic root in the textbook is preceded by the square root and followed by the root sign. It is convenient to study the properties of the root and perform the operation of the root, because the square root of a positive number has two values, and the two values are opposite. Therefore, to study the properties of quadratic roots, we only need to study the properties of arithmetic square roots. The appearance of arithmetic root solves the feasibility and singleness of square root operation in real number range, thus paving the way for studying root formula and playing a connecting role in conceptual system. Second, put forward the definition to promote understanding. The definition of the concept is a summary of the essential attributes of the object we are studying, and the wording is more refined, and each word has its important role. In order to deeply understand the meaning of concepts, teachers should not only pay attention to the rigor and accuracy of words used in concept discussion, but also correct some improper conceptual mistakes in time, which is conducive to cultivating students' strict logical thinking habits and gradually developing the good habits of delving into definitions, word-for-word analysis and careful deliberation. For example, when explaining the concept of isosceles triangle, we must emphasize the word "you" with two equilateral sides, rather than the word "only" with only two equilateral sides. There are two situations in which the first two sides are equal: one is an isosceles triangle with only two sides equal, that is, an isosceles triangle with unequal waist and bottom; Second, an isosceles triangle with three equilateral sides is also called an equilateral triangle. The latter involves only one case, excluding the special case that an equilateral triangle is also an isosceles triangle. Another example is "A, B and C are not all equal to zero" and "A, B and C are not all equal to zero". These two definitions are the same, but in different positions, but their meanings are completely different. For another example, if three points are not on the same line to determine a circle, if it is rewritten as three points to determine a circle, a new proposition will be obtained, including both three points on the same line and three points not on the same line, but three points on the same line cannot determine a circle, that is, any three points on the circle are not on the same line. Therefore, it is not valid to determine a circle by writing three points that are not on the same line. Therefore, when talking about this concept, we should highlight the sentence "not in a straight line". Third, the relationship between the old and the new, positive and negative contrast Some concepts are simply difficult for students to accept and master. However, if some related or relative concepts are put together for analogy and comparison, so that students can not only understand their relationship, but also notice their differences, it will open their eyes and find another way. The relationship between two concepts can be divided into two types: compatibility and incompatibility, and compatibility can be divided into three types: identity, intersection and subordination. For example, positive integers and natural numbers are the same, square roots and arithmetic square roots are subordinate, square roots and roots are cross-related, rectangles and diamonds are cross-related, and parallelograms and trapezoid are incompatible. For another example, when talking about "elevation angle" and "depression angle", it is not difficult to distinguish who is "elevation angle" and who is "depression angle" by comparing these two concepts. Another example is "central angle" and "peripheral angle". Students already know that the "central angle" is the angle whose vertex is at the center of the circle. From this, most students can get the definition of "circle angle": the angle of the vertex on the circle is called "circle angle", which is just wrong. At this time, the teacher will describe the definition of "rounded corners" again, and students will feel suddenly enlightened. In this way, by comparing the concepts of "central angle" and "peripheral angle", it is clear and clear. A deep understanding of mathematical concepts is the basis of improving students' ability to solve problems; On the other hand, only by solving problems can students deepen their understanding of the concept, and understand and master the connotation and extension of the concept more completely and profoundly. There are many examples of solving problems directly with concepts in textbooks, so we should make full use of them in teaching. At the same time, in view of the concept that students are prone to make mistakes in understanding, some targeted topics are designed, so that students can understand the concept more thoroughly through practice and comments. 4. In-depth analysis reveals that the concept of essential mathematics is the basis of mathematical thinking. In order to make students have a thorough and clear understanding of mathematical concepts, teachers should first analyze the essence of concepts and help students understand the connotation and extension of a concept. That is, the object reflected by the concept is clearly defined from both qualitative and quantitative aspects. For example, mastering the concept of vertical lines includes three aspects: ① understanding the background of introducing vertical lines: when one of the four angles formed by the intersection of two straight lines is a right angle, the other three are also right angles, which embodies the connotation of the concept. ② Knowing that two straight lines are perpendicular to each other is an important special case of the intersection of two straight lines, which embodies the extension of the concept. (3) I will use the definition of two perpendicular lines for reasoning, knowing that the definition has the function of judgment and nature. In addition, students should learn to solve problems with concepts and deepen their understanding of the nature of concepts. For example. "Formula (a≥0) is generally called quadratic radical", which is a descriptive concept. Formula (a≥0) is a whole concept, in which a≥0 is a necessary condition. For another example, in teaching the concept of function, in order for students to better understand and master the concept of function, it is necessary to reveal its essential characteristics and analyze it layer by layer: ① "there is a certain process of change"-explaining the existence of variables; ② "There are two variables X and V in a certain change process"-the representation function is to study the dependence between the two variables; (3) "For every certain value of X within a certain range"-means that the value of the variable X is limited, that is, the value range is allowed; (4) "V has a unique definite value corresponding to it"-it means that there is a unique definite corresponding law. From the above analysis, we can see that the essence of function concept is correspondence. In a word, mathematics concept teaching plays a vital role in the whole mathematics teaching. Teachers should try to cultivate students' dialectical materialism concept by revealing the process of concept formation, development, consolidation and application. Improve students' cognitive structure and develop students' thinking ability, thus improving the quality of mathematics teaching.