Abstract: Based on the design principle of a new type of opposed-piston hydraulic-output engine (OPHO),a mathematical model was established according to the working principle of the synchronization drive mechanism,and the multi-body dynamics software Adams was used to build the simulation models separately for this mechanism and the conventional crank-link engine to analyze the force of the critical moving parts of the synchronization drive mechanism.The dynamic simulation results show that,compared to the crank engine,the lateral force on the power piston of OPHO engine in the vertical direction is small,which is conducive to reducing the mechanical loss between the piston and the cylinder wall,thus alleviating the phenomenon of cylinder wall wear and extending the life of engine and its parts to a certain extent.On the other hand,the synchronization drive mechanism is of symmetrical arrangement,the vibration and the force of the engine in the horizontal direction can be counteracted,and the overall balance of the engine is better.