No. 10-2 coal seam fully mechanized mining of Xinsan Mine was taken as study object, the law of different mining height with 3.5,4.5 and 5.5 m of support resistance of working face, caving rule and stability of coal wall was analyzed, With the increase of mining height, the support resistance of working face and mining rate increased, coal mining difficulty and coal wall stability decreased, the technology provided reference for similar mines with large mining height.