Abstract: The foundation of a wind turbine pile is the load of the wind turbine itself and the lateral pressure of the blade rotation, and the stability of a pile foundation is very important. The offshore wind turbine pile is not only influenced by the tidal current and wave interaction, but also the scale of the pile foundation, which is usually between the pier and the pile foundation, and its local scour has some particularity. By establishing a normal model of 1∶60, the local scour of the offshore wind turbine pile foundation under the action of wave, tidal current and wave current is studied. The research results show that: ①the tidal current is the dominant factor in controlling the local scour of the pile foundation in the sea area; ②under the action of the alternating flow, the shape of the scour hole is oval, and the maximum scour depth is about 0.8 of the steady flow; ③under the wave-current interaction, due to the role in the front of the pile wave oscillating flow, sediment is easier to move than the current action, the local scour is significantly enhanced, and the maximum scour depth is 2.0 and 1.7 times under the action of tidal current and constant flow; ④the calculated values given by the Han Hai-qian formula are in good agreement with the experimental values of the scour depth of the pile foundation under the influence of the coefficient 0.75. According to the test results, it is suggested that the riprap protection of local scour around the pile foundation pit should be done in order to ensure the security and stability of the offshore wind turbine.