Abstract: A double-half-rotation legged-robot with auxiliary supporting wheel was proposed. It was mainly composed of one body bracket, two wheel-legs, some wheel-leg brackets, auxiliary supporting rods and rolling wheels. The virtual prototype model of the robot was established with ADAMS simulation software, the constraints among the leg-rods, the three-dimensional collision attributes between the leg-rods and the road surface were set, and the rotate speed of each joint was also set according to the kinematic coupling of each leg. Aiming at the condition of robot walking on flat ground, the curves of displacement, velocity and acceleration of the body bracket centroid with time were achieved by virtual simulation analysis with ADAMS, and the contact force between the wheel-leg and the ground was also obtained. The results show that the robot has a relatively small fluctuation in vertical direction, and the springs arranged at the auxiliary supporting rod are effective on vibration reduction.