Abstract: To eliminate the damage of the mined-out area generated by early small coal mining in Pingsuo East Open Pit Coal Mine to the normal exploitation，blasting drilling holes at mined-out area are detected and pretreated from the view of the origin of the mined-out area.The air interval implements at penetrated hole bottom are adopted to treat the holes by alternating packing with 0.6 m，0.4 m of rock slags.The treated penetrated hole plays a supporting role for massive charges at upper part.In view of problems of low collapse rate and low collapse depth faced in blasting production of the mine，the blasting parameters are optimized.The mathematical statistics and engineering measurement methods are used to contrast the blasting parameters before and after optimization.By changing the borehole-net parameters，charge structure，connection methods and other technical measures，the upper cover layer are collapse and filled into the goaf，thus improving the collapse and blasting effect.The practicality of the optimized blasting parameters is verified，which provides security for subsequent coal mining.

Key words: Treatment of goaf, Collapse blasting, Parameter optimization, Application