Abstract:degree rotating nozzle was introduced into water jet propulsion system. Based on the comprehensive analysis of the kinematic characteristics and amphibious environment adaptability of the existing amphibious robot, an amphibious vector water-jet driving device is designed by combining hollow driving wheel and axial-flow blade. Based on the momentum theorem and the theory of pressure and energy loss in the flow-path, the prediction of two-dimensional thrust and motor speed of amphibious water jet drive device was established. Based on the principle of energy conservation and viscous resistance moment, a prediction model of driving motor torque was established. CFD simulation of the device was carried out to obtain the flow characteristics such as pressure and velocity in the inner channel of the propeller. Finally, a wheel-pump combination amphibious thruster was made and tested under water. The thrust of the micro-wheel-pump combination amphibious thruster with a characteristic size of is 6.5 N at a speed of 2 800 r/min. The comparison error between the experimental results and the simulation results is less than 8%, which verifies the effectiveness of the configuration and the two-dimensional vector thrust characteristics.