Abstract: In order to solve the top-coal caving difficult problem which result from large top-coal strength，theoretical analysis and numerical simulation was applied to obtaining cracks development and cracks circle range after deep hole blasting.Results showed that crack circle range of top-coal was about 1.5m after blasting with 94mm borehole diameter and 75mm cartridge diameter，and rational borehole space was obtained to be 3m.On the basis of this，top-coal deep hole blasting project of 11301 mining face was designed.Topcoal recovery had been obviously increased after application.