To reveal the characteristics of climate and environmental changes in the Baiyangdian area during the late Pleistocene and their future evolutionary trends, a comprehensive analysis was conducted on the climate dry and wet changes in Baiyangdian since the late Pleistocene (26. 9 ka B. P.) by analyzing the grain size characteristics of lake sediment in a borehole in the southern part of Baiyangdian, combined with chronological data. The results show that in the period of 26. 9 ~ 10. 5 ka B. P. , the area mainly tubidity current deposit under deluvial and alluvial function, and the climate is in the recovery process in the post glacial age, but generally dry. In the period of 10. 5 ~ 8. 3 ka B. P. , the depositional environment is mainly fluvial facies deposit, and the climate is warmer and moister than in the previous period. During the period from 8. 3 ka B. P. to the present, the dipositional environment has gradually transitioned from fluvial facies deposit to lake facies deposit, and the climate has become mainly warm and moist glacial climate, reached the period of the warmest and moistest climate since the end of the Late Pleistocene epoch in the mid-Holocene (about 6. 6 ka B. P.) , and then gone through two times of remarkable cold-arid fluctuation around 3. 2 ka B. P. and 1. 8 ka B. P. Baiyangdian started to shrink and disintegrate under the impact of geological structure and rivers' vicissitude, and finally formed the modern patterns of Baiyangdian Lake, under the interference of human activities. In summary, due to the influence of monsoon evolution, the environment in North China during the last glacial period is cold and dry. It begins to turn wet in the early Holocene, is the wettest in the middle Holocene, and became dry in the late Holocene. This lake evolution model is similar to the evolution model of the East Asian summer monsoon, and has important reference value for understanding the future monsoon evolution model under the influence of human activities.