The stability of platform structure is the most basic guarantee for safety operation of offshore wind turbine. In order to compare the stability of platform structures,the paper established three kinds of floating wind turbine models based on TLP, spar and barge. Based on the finite element method and combined with multi-body dynamics method, the time-domain response and frequency-domain performance on the wind, wave and current conditions were researched.It got different kinds of wave forces trend along with the change of wave frequency. The result shows that the movement amplitude and wave forces by the platform appeared large response under the effect of low frequency waves. Barge has a more obvious dynamic response than the spar and TLP under the extreme sea condition.