Against the backdrop of continuous global temperature rise, the amount and distribution patterns of precipitation in the Daqing River Basin have undergone significant changes. Understanding the evolving dynamics of precipitation within this basin is therefore of strategic importance for improving flood control and disaster mitigation efforts. Based on 50 years (1974–2023) of daily precipitation data from 36 meteorological stations across the Daqing River Basin, this study applies the Morlet wavelet transform to analyze the spatial distribution of precipitation, its variations across different time periods, and the underlying periodic patterns. The results reveal that the temporal distribution of precipitation across various timescales exhibits nested multi-scale periodic structures. Moreover, there is a clear similarity between the precipitation during the flood season and the annual average precipitation, both dominated by periodicities around 5, 16, and 28 years. Variations in flood season precipitation exert a notable influence on the annual precipitation cycle. Given that we are currently in a period of abundant precipitation, the research results provide a basis for a deeper understanding of precipitation patterns in the Daqing River basin. At the same time, the multi-time-scale precipitation cycles identified in the study provide scientific reference for predicting high-risk flood periods, optimizing reservoir operations, and formulating flood control and disaster mitigation policies.