Taking the withdrawal passage of 22311 fully mechanized working face in Huojitu Well of Daliuta Coal Mine as the research background, theoretical calculation and FLAC3D numerical simulation software were used to analyze the critical instability width of the withdrawal passage coal pillar, which is about 4m; The length of "long key block B" is about 21m. The structural mechanics model of "long key block" on the roof of the withdrawal passage is established, and the expression of the critical resistance of the hydraulic support under the action of the maximum "long key block" in the fully mechanized mining face is derived. The critical resistance of the hydraulic support is 10526kN, and the margin coefficient of the critical resistance of the support (rated resistance/critical resistance) is about 1.14; In view of the problem that the surplus system of the critical resistance of hydraulic support is insufficient, which is easy to cause severe rock pressure accidents such as adjacent support pressing, malignant roof caving (leakage) or wall fragmentation, the multi technical means of combined support with anchor cables, stoping mining to give way to pressure, reinforcement and reinforcement are proposed to jointly control the stability of the surrounding rock of the withdrawal passage, and they are used in field tests, and have achieved good control effects. This study provides a reference for the stability control of the withdrawal passage in this mine and other mines with similar conditions.