Abstract: In order to fully hold the factors affected to the stability of the high cutting hydraulic powered support,the paper analyzed the instability mechanism of the hydraulic powered support applied to the high cutting coal mining face.A critical instability mechanics model of the high cutting hydraulic powered support was provided. Based on a high cutting hydraulic powered support as an example,the status parameters were substituted to the critical instability mechanics model of the high cutting h ydraulic powered support and the theoretical analysis on the critical instability of the hydraulic powered support was obtained.The numerical analysis software ADAMS was applied to establish the multi-body dynamics model of the hydraulic powered support and the numerical solution of the critical tilt of the hydraulic powered support under each performance was analyzed and obtained. There was a difference of 2% between the comparison theoretical analysis and the numerical simulation results an d the accuracy of the model established and the feasibility of the simulation method was verified.The instability angle curve of the powered support obtained from the 0 bservation could obtain the instable tendency of the powered support at each height and thus could provide technique method to the stability control of the high cutting hydraulic powered support.