Aiming at the technical problems of gas extraction and drilling difficulty and low extraction efficiency in the islanding working face of Wangpo Coal Mine, the stress distribution characteristics and dynamic evolution law of the islanding working face under the pressure of huge roof were studied deeply by combining theoretical analysis, numerical simulation and field monitoring. In isolated working face coal internal stress distribution and deformation of rock mass failure characteristics, on the basis of combination of drill, drill upgrade, crushed under complex stress conditions is established the construction technology of soft, gas coal seam drilling system, and through the study found that the plug type connection way forward + reverse spiral drill pipe form strong rotary hole and assisted with nitrogen gas discharge, It can significantly improve the efficiency of slag removal during drilling, and is more conducive to efficient borehole formation under complex formation conditions. The optimized drilling technology can effectively improve the drilling efficiency, provide a new idea for breaking through the technical bottleneck of gas pre-drainage drilling in crushed soft coal seam under complex stress conditions, and also provide a basic guarantee for gas efficient pre-drainage and coal mine safety production.