Abstract: Based on the small-scale level of a single mining unit, Coal mining subsidence crack distribution is measured by GPS, total station is used to determinate horizontal movement and deformation, the relationship between horizontal movement and deformation and visible width of dynamic coal mining subsidence crack is analyzed on the basis of counted visible width of dynamic coal mining subsidence cracks; Different measured points gap are compared with the corresponding predicted subsidence values along the marginal crack; The damage to the land due to ground crack is analyzed in the horizontal and vertical direction respectively, the smaller subsidence coefficient confirms the fact that the vertical soil damage, based on this, the fact that dynamic ground cracks will cause severe damage to the land in the short-term is pointed out, the damage to the land due to the marginal crack takes a long time and needs key harnessing; Combined with mining subsidence, the fact that strata movement due to mining is the contact to land damage caused by cracks is proposed, the power from the conversion of the gravitational potential energy and land stress potential, the characteristics that the thin bedrock and thick unconsolidated layers rapid spread movement deformation exacerbate the destruction to land due to crack in the early days of mining influence.