The construction of earth rock dam is mostly used in the way of stratified compaction and step by step construction，taking the degree of compaction and the optimum water content as the design control standard，the strength and compression characteristics of the dam directly affect the stability of the dam.In order to investigate the effect of compaction on stress deformation，based on the reasonable simulation of dam construction process and the selection of different compaction degrees，by using the finite element simulation of dam layered rolling process，analysis of different filling height and degree of compaction effect of stress deformation and slope stability of the dam.The study shows that stress deformation and slope stability are closely related to the degree of compaction during the construction period，and the influence of high dam is more obvious，strict control of compaction standard can effectively reduce the settlement deformation of earth rock dam.