In order to solve the problem of easy destabilization and collapse of gas extraction holes in soft coal seams, full-length sieve pipe protection technology was proposed for large diameter gas extraction holes, and technical equipment such as straight bit and hollow spiral drill pipe were developed, which can increase the length of devolved sieve pipe protection to more than 100 m. In Zhongxing Mine 3205 working face, several groups of gas extraction holes were constructed, connected to the extraction system and the gas flow, concentration, pressure and other parameters of each group were measured and analyzed. The results showed that the extraction volume and gas concentration of large diameter gas extraction boreholes with full-length screen pipe protection technology significantly increased, and the cumulative extraction volume at the end of the test was more than 32% higher than that of large diameter gas extraction boreholes without this technology, which was about 4.4 times of that of normal diameter gas extraction boreholes, and the extraction effect was significantly improved.