The multi-scale variation characteristics of precipitation heterogeneity in Guangdong are studied to provide bases for dealing with drought and flood disasters as well as water resources utilization scientifically. Based on daily precipitation data from 86 national meteorological stations in Guangdong Province from 1973 to 2023, we analyze the spatio-temporal variation patterns of the intra-annual precipitation distribution heterogeneity characteristics in Guangdong Province by using the precipitation concentration degree (PCD) and precipitation concentration period (PCP) at different time scales, variable coefficient, Sen''s slope trend coefficient, and Hurst index. The results indicate that the PCD in Guangdong Province varies from 0.32 to 0.57, and the spatial distribution is characterized by being high in the south and low in the north. The PCP generally shows a quasi-latitudinal distribution of "early in the north and late in the south". In terms of daily, dekad and monthly scales, the precipitation is mainly concentrated in the periods from May 21st to August 21st, from the last dekad of May to the last dekad of August, and from May to August. When the annual precipitation was at a high level, the intra-annual precipitation distribution tends to be more uniform, and the PCP tends to come earlier. The overall change trend of the PCD is not significant, ranging from −0.002 4· year−1 to 0.001 9· year−1, and its change trend in the future period is the same as the historical evolution. The daily and dekad scales of precipitation can more finely characterize the precipitation heterogeneity characteristics in Guangdong Province than the monthly scale, and the PCD and PCP have obvious regional differentiation characteristics.