Taking a new steel tube rotating mechanism as the research object, the model is simplified and the virtual prototyping model of the mechanism is established. The mechanism kinematics simulation is carried out with ADAMS simulation software. The motion law and state in two conditions are comparatively analyzed. Analysis results show that, in steel tube clamping stage the motion of the clip rod is of variable deceleration; And in rotating stage, mechanism is of accelerated rotation with variable acceleration when the cylinder input, while mechanism is of uniform rotation when the crank input； And then the cylinder is with positive and reverse swings throughout the movement process. The analysis results provide the basis for institution parameter selection and structure optimization design.