Abstract: Using the precipitation data of Xuanhan National General Meteorological Station from 1959 to 2019, the characteristics of precipitation changes in Xuanhan was analyzed with mathematical statistics. The results show that: (1) Since 1959, the annual precipitation in Xuanhan has shown an increasing trend, and the climate trend tendency rate is 12.678mm/10a. (2) The average annual frequency of heavy rains is 4.7times/a, and the distribution is relatively even. The climate tendency rate is 0.1times/10a, which is concentrated in the period from Jun to September, and the largest proportion is in July, nearly 30%. The average frequency of heavy rainstorms is 0.5times/a, and the distribution is uneven. The frequency has increased in recent years, with the largest proportion in July. Heavy rains accompanied by short-term heavy precipitation in various precipitation periods, short-term heavy precipitation mainly occurs from early morning to morning, accounting for about 73.8% from 0:00 to 12:00, among which the most occurs from 8:00 to 10:00. (3) The annual precipitation has obvious periodic changes at the three scales of 23~30a, 12~20 a, and 4~10a. Among them, the 23~30a scale is representative, and there are three relatively complete oscillation cycles. (4) The frequency of torrential rains changes significantly in the three-scale cycles of 25~32a, 13-20a, and 4~10a. Among them, the 13~20a scale performs better, with 6.5 complete shock cycles.