The whole machine models for Spar platform supported offshore wind turbines were built to research the dynamic response and wave force components and their variation trend with water depth. Hydrodynamic calculations were carried out considering wind, wave and current load to obtain the frequency-domain performance and time-domain responses and further the study of researching the impacts of water depth on the dynamic performance. The results show that dynamic responses of Spar supported offshore wind turbines are apparently influenced by water depth.