Abstract: Based on the system viewpoint,the bond graph method was introduced into the modeling and analysis of wave energy system.Taking the hydraulic two-body wave energy conversion system as an example,the system bond graph was constructed and the state equations were given. The simulation analysis was implemented by setting the parameteys,and then the reliability of simulation results was verified by model experiment. The relative heave displacement,hydraulic cylinder piston force and accumulator outlet pressure were compared respectively. The simulation result curves show a high degree of coincidence with the experimental test results,and the relative difference of each parameter is basically controlled within 5%. Results show that the bond graph method can be used as an important tool for the design,optimization,and evaluation of wave energy conversion systems.