Abstract: Using wave energy conversion Sharp Eagle Ⅱ as study objective,this paper establishes an group of motion equations of WEC for frequency domain dynamic response calculation and hydraulic damping optimal design in Wanshan island sea area wave condition.The main content is divided into three parts:firstly,building the motion equations in frequency domain;secondly,calculating the equations and obtaining the optimal damping,motion amplitude and main structural point force etc;thirdly,developing the hydraulic load design of the energy conversion system and providing WEC strengthen design data.The results show that the WEC energy capture width ratio is related to hydraulic damping and wave frequency;the maximum energy capture width ratio of WEC Sharp Eagle Ⅱ reaches300% for 3-6 seconds wave and reaches 200% for the test area wave of Wanshan island in Zhuhai.