Abstract: Under the action of high dynamic load in the underground, the fatigue failure of hydraulic support usually occurs. The fracture position is generally at the welded joint, and there is serious stress concentration. In order to study and further improve the fatigue strength of hydraulic support, the finite element analysis method is used in this paper to analyze the possible location of fatigue failure. Fatigue tests are carried out on different forms of welded joints for the dangerous parts, and the main factors of fatigue damage of hydraulic support are obtained. This study will provide a theoretical reference for the fatigue design of welded structure of hydraulic support.