Abstract: To improve the technology regarding oscillating float-type wave conversion,a single buoy wave power device was proposed.Motion characteristics of a single buoy on the waves were studied. Wave energy was converted into oscillating mechanical energy of the oscillating buoy,and transmitted to the PTO system（energy conversion system）. By CFD method（Star-CCM Software）to analyze the motion and load changes of the buoy under different conditions of the PTO conversion system,motion characteristics of the buoy with different damping parameters were acquired. The results provide a theoretical basis for later optimization of the device and actual sea tests.