Confucius, an ancient educator in China, said, "Knowing is not as good as being kind, and being kind is not as good as being happy." Interest is the best teacher. Modern psychological research also shows that learning interest directly affects learning effect. In order to establish students' confidence in learning mathematics well and stimulate their interest in learning mathematics, we compiled the book "Junior Middle School Mathematics Fun", aiming to tell students that mathematics is not boring, but full of fun.