Abstract: According to the present status on the insufficient setting load of the double telescopic leg in the hydraulic powered support, an analysis was conducted on the working principle, operation procedure and structure stressed.The analysis showed that during the active setting load of the leg, the internal force occurred by th e one level cylinder piston hit the guidance sheath could cause the pressure insufficient of the second level cylinder and thus the setting load would be 50% lower than t he rated value.Taking the口360/0260-2340 mode double telescopic leg as the study object, a setting test was conducted.The test data showed that the insufficient setti ng load would cause the roof subsidence value increased by 13.67 mm.In order to make the double telescopic leg of the hydraulic powered support reached to rated set ting load, five methods of the mechanical resistance one level bar chamber method and others were put forward and each features was analyzed which could provide re ferences to the design of the double telescopic leg of the hydraulic powered support.