Abstract: Array layout is a future trend of buoy-type wave power generation devices. To study its hydrodynamic performance, a new system using array buoys has been developed and its working principle is described in this paper. We make theoretical analysis of the hydrodynamic characteristics of an oscillating buoy, present a simulation model developed for this new buoy system, and analyze the frequency response RAO values for a single buoy in different drafts using the hydrodynamic analysis code AQWA. An engineering prototype was designed and its sea trial tests were carried out. Using the test data, the theoretical analysis and simulation results were verified. Test results show that optimization of the buoy array layout can significantly improve the stability of power output and efficiency of the generation system. This study would lay a basis for designs and further optimization of the structure of array buoy devices.