Lifting system is the core component of the power catwalk whose continuity and stability are key performance. As for a new type of power catwalk, lifting system are 2DFO mechanism whose executive bodies are hydraulic motors and doubleacting hydraulic cylinders. So the lifting system is a nonlinear system with dualinput, singleoutput and coupling. The angle between the drill pipe and the ground is control variable which is required to be unchanged when drilling pipe is going to reach the drilling table in order to realize the continuity. The speed of the lifting system was analyzed and the relationship of the two input variables and output variables was found. The velocity relation was linearized and different control strategies were compared in effect and feasibility, ultimately the control strategy that the speed of motor is uniform as same as that the speed of doubleacting hydraulic cylinder is changed was adopted. Through cosimulation of LMS Virtual.Lab Motion and AMESim, the forces and smooth of lifting process was analyzed. Simulation results indicate that the principle of method is correct and meet the practical requirements.