Abstract: This paper mainly studies the surface change caused by “three under” coal mining, and then analyzes the subsidence mechanism around the mining area. Five observation lines are mainly arranged for the surface along the mining direction and the vertical direction of the working face. The field observation data are obtained by using the electronic level of trimble. The change curve is analyzed by using the settlement observation analysis software and SPSS data analysis software, and the mining situation is analyzed in time. The data of “three under” coal mining face adopted in time has obtained theoretical and scientific basis for mining subsidence, land compensation and comprehensive utilization.

Key words: “three under” coal mining, working face, subsidence, subsidence mechanism