Abstract: To propose the mechanical relationship between the support and the surrounding rock of the large-scale high-level fully mechanized top coal caving mining face, and to derive the calculation formula of the working resistance of the hydraulic support, the 13# coal seam mining of Xiegou Coal Mine is used as the engineering background, and the theoretical analysis method is adopted. The research was carried out and verified by numerical simulation and on-site observation. When the 13# coal seam is mined, the maximum support resistance of the working face is 16 978.3 kN, and the support strength is about 1.39 MPa. The 3DEC simulation results show that when the support strength is 0.8 MPa, there is a risk of pressure on the working face. When the support strength is 1.2 MPa, the reasonable pressure relief method can better control the roof and support. When the strength is 1.6 MPa, the roof can be safely controlled; the on-site ore pressure observation shows that the maximum load of the bracket during the mining process is 16 182 kN.