Using the hourly precipitation data of nine conventional stations and 287 automatic weather stations during the flood season of May to September along the eastern Helan Mountain in Ningxia, China, the temporal and spatial characteristics and oscillation periods of the rainstorm were analyzed in this study using the linear trend coefficient, Kriging interpolation, and Morlet wavelet transform. First, we recorded the highest rainstorm days in the 1960s, intensity in the 1970s, and contribution rate from 2011 to 2019. Second, the average annual number of rainstorms along the eastern Helan Mountain from 1961 to 2019 was 2.1 d, and the rainstorm intensity was 46.6 mm·d^-1. Third, the number of rainstorm days showed a downward trend of 2.1 d·(10a)^-1, and the rainstorm intensity depicted a little change trend. The rainstorm contribution rate had a weak upward trend of 1%·(10a)^-1 from 1961 to 2019. Fourth, rainstorm mainly occurred in July and August, with more concentrated rains from mid-July to mid-August. Fifth, 810 short-term heavy precipitations were observed in different periods along the eastern Helan Mountain, which mainly occurred at 21:00-22:00 and 16:00. Accordingly, 57.8% of the rainstorms occurred at night. Sixth, the number of rainstorm days showed periodic changes of 2-6 a and 7-15 a, with the first main period of change being 3 a. Meanwhile, the rainstorm intensity depicted periodic changes of 2-4 a and 5-16 a, with the first main period of change being 9 a. Seventh, the area with the largest number of days, strongest intensity, and largest magnitude of rainstorm was mainly distributed in the mountain area of Yinchuan to Shizuishan of Helan Mountain. Lastly, the flood disaster along the eastern Helan Mountain was characterized by high frequency, wide range, obvious seasonality, regional concentration, strong destructivity, and great loss.