In the process of coal mine ， when the length of working face advancing to start lengh， ， the surface  sunk ahead of working face along with working face advancing， and with the increase of the mining degree ， the advanced impact length increased at first and tended to stability. In order to study the relationship between advanced impact length and mining degree based on shallow buried and intensity mining conditions， the UDEC simulation software were utilized and it's verified by data in Halagou Colliery.The results show that the advanced impact length lags behind working face a certain distance when the working face arrived at the start length in the shallow buried and intensity mining conditions;with the increase of mining degree， the advanced impact length gradually increased and then decreased to a stable value. It has a certain reference significance for the study of the surface movement dynamic situation in shallow buried and intensity mining conditions.