A mathematical model is proposed for predicting static water resistance of offshore wind turbine installation vessel and to calculate the resistance of a certain type of offshore wind turbine installation vessel. In order to verify the efficiency of this mathematical model, the comparison between results calculated by it and actual model test has been made. The conclusion indicates that the estimation method is reliable, and it can provide reference for resistance calculation of similar type vessels. Currently in China, there are no references for the effective prediction and calculation of the resistance for offshore wind turbine installation vessel. Therefore the proposed method has important value of engineering application in the areas of effective resistance estimation method of offshore wind turbine installation vessel, as well as the numerical calculation of ship hydrodynamics.