The frequent occurrence of sand and dust causes serious harm to the ecological environment and public health in arid and semiarid regions. The risk of population exposure depends not only on climate change but also on the population size and spatial distribution of sand and dust. However, systematic evaluations of long-term exposure to dust are still insufficient. Based on the theory of environmental similarity, this study integrated data from sand and dust monitoring stations and nine environmental variables. Using the random forest method to construct a simulation model of sand and dust intensity, combined with population data to establish a sand and dust population exposure risk index system, and evaluated the spatiotemporal evolution of sand and dust intensity and population exposure risk in northern China from 2000 to 2020. The results showed that \mathrm{①} the coefficients of determination of the dust intensity model were all greater than 0.6 (p<0.01). The three most influential factor with the highest contribution to the model were the drought index, wind speed, and NDVI. \mathrm{②} Sand and dust intensities in the study area showed significant spatial heterogeneity. The extremely high, high, and high intensities of sand and dust were mainly concentrated in Northwest China, while the extremely low, low, and low intensities of sand and dust were mainly concentrated in North and Northeast China. During the study period, the sand and dust intensity decreased by 53%, and the extremely high- , high- , and high-intensity sand and dust areas of 1.9×10⁶ km² were transformed into very low, low, and low sand and dust areas. \mathrm{③} In northern China, 350 million people are exposed to dust and sand, and high-risk areas of dust exposure are concentrated in the Beijing-Tianjin-Hebei region, southern Shaanxi and Shanxi provinces with high population density, and southern Xinjiang with high dust intensity. The overall risk of exposure to sand and dust in the study area decreased significantly, with 73 million people exposed to extremely high, high, and high-intensity sand and dust. The findings reveal the spatial and temporal distribution characteristics of sand and dust exposure risk in northern China and provide a scientific basis for local governments to formulate targeted sand and dust prevention and control measures.