Abstract: According to the shallow sampling depth, inaccurate measurement and control of sampling position, large gas loss and other disadvantages existed in the available sampling technology for measuring gas content in broken soft coal seam, a sampling technology for measuring gas content in broken soft coal seam was proposed based on comb-shaped directional borehole, its technical principle, process flow and technical advantages were introduced, matching drilling and sampling equipment such as mine closed coring device, directional drilling rig and mud pump truck were selected, the key technologies were developed such as double dynamic compound slag discharge and directional drilling technology in main hole, exploration technology of coal seam occurrence while drilling by probe branch hole, closed coring technology in sampling branch hole. The field test was carried out in the broken soft coal seam in No.94 mining area of Qidong Coal Mine, 2 comb-shaped directional boreholes were completed, and closed coring was carried out 3 times and the sampling success rate was 67%, the maximum sampling depth was reached 484 m, the occurrence and gas content of the target coal seam were found out.