The 3D terrestrial laser scanning(3D TLS) was used to the observe the experiment of similar material model,then we built the 3D digital model based on the scanned point-cloud image,obtained the 3D coordinates of targets on the model every period by feature extraction,and drew the dynamic curves of earth surface subsidence with the mining face progress.This way to establish the 3D model could overcomes the limitation of traditional methods that can't get data when the model was damaged,to represent the course of fracture and collapse of the top plate afterwards,which provided a new approach to the comparison research on ground surface measurement and the data from model.