The hard roof has the characteristics of large pressure step distance and high strength, which causes great damage to the roof support and seriously threatened the safe mining. The roof accident is one of the four major accidents of underground coal mining. The working face 13302 of Du’erping mine was taken as an example, the damage of hard roof and the mechanism of blasting unloading pressure was introduced, the blasting parameters were optimized based on numerical simulation, providing reference for roof management.