The cutting process parameters are crucial to the rock layer control and pressure relief effect in the coal mining process. In order to explore the key parameters of blasting and cutting roof in No. 9109 cutting roadway in Lunan No.9# coal mining area of Xinjing Mine, the effects of 3, 6, 9 and 12 m cutting top height and 55°, 65°, 75° and 85° cutting top angles on the vertical stress distribution of the stope were studied by numerical simulation method, and field industrial tests were carried out. The numerical simulation showed that when the cutting top height was 9 m and the cutting top angle was 75°, the influence range of the leading support pressure could be effectively reduced, and the stress concentration degree could be reduced. After the implementation of the pre-cracking blasting and cutting top process, the moving amount of the top and bottom plates was monitored, and the monitoring results showed that the pre-cracking and blasting cutting roof successfully cut off the stress transfer effect of the overburden, so that the moving amount at the top of the roadway was significantly reduced, and the pressure relief effect was obvious. This was of great significance to ensure the safe production of coal mining projects.