Abstract: In order to solve the problem of large weighting step, strong ground pressure behavior and hard to management with the hard roof. Serving the mine of ka wa zhang as the engineering background. After calculating the roof’s fall across interval in theoretical, proposing roof weakening scheme of cut blasting and ahead of pre-splitting blasting in the roadway. Measuring the strata pressure data in the scene and analysing the condition of strata pressure. The results show that: the hard roof has strong integrity and good mechanical properties, besides its initial and periodic weighting interval are large. Through taking the technology of forced caving of blasting , the hard roof’s compressive strength has been reduced and it ensure the mine to have a safe and efficient production.