Abstract: Through the numerical simulation study of the caving interval before and after weakening top coal and roof stress behaviors of 3407 working face, the results show that the roof weighting step of immediate roof and main roof is 12 m and 31.2 m before weakening working face, and the weighting step of immediate roof and main roof is 7.2 m and 21.6 m after weakening working face; the initial weighting was shortened obviously after weakening. The vertical stress of blasting roof increases faster than the stress before weakening the working face, and generally the vertical stress after weakening the roof is slightly larger than the vertical stress before weakening the working face. The extent of the damage of top coal after weakening the roof is higher than the extent before weakening working face, so that the top coal can be fully broken and the top coal recovery rate can be improved in the end.