From the perspective of energy security, the development of renewable energy can solve the shortage of energy resources. From the perspective of environmental protection, the development and utilization of renewable energy can improve the deteriorating ecological environment in China. The equipment of river kinetic energy generation is different from that of conventional large and medium-sized high dam hydropower stations because of the different energy conversion modes. Due to the great differences in river conditions, the development of wave energy in China can not directly apply the successful experience of foreign countries. The mathematical model of motion simulation is based on the simulation of mechanism system. It can truly reflect the motion performance and energy utilization of a given mechanism to a certain extent. In this paper, the mathematical model of the motion simulation of the tank test model is established by analyzing the motion of the blade hydrodynamics and the pendulum energy conversion device. The device capture power obtained by experiments is compared with the device capture power obtained by the frequency domain numerical model, which verifies the rationality of the experimental arrangement and the reliability of the experimental data.