Xu Senlin's Mathematical Analysis (Yellow Paper) is the best, but some topics are extremely difficult. Its author is a student of mathematician Wu Wenjun. He developed the method of teaching mathematics (especially mathematical analysis) created by Wu Wenjun in the University of Science and Technology of China (this method is called "Long Wu" in the University of Science and Technology of China), which is very NB.

Recommend more books: (If your family is rich, it is strongly recommended to buy all of them, otherwise you can buy one or two books as appropriate)

1. Typical Problems and Methods in Pei's Mathematical Analysis

2. Nankai, Fudan and Peking University. (great classic)

3. China Normal University is above average. Very clear, not too difficult, can increase confidence.