In order to establish an accurate equivalent model of a hybrid offshore renewable energy conversion farm, a non-mechanism equivalent modeling method is proposed. Based on transfer functions,a non-mechanism equivalent model was developed to describe the nonlinear relation between inputs and outputs. Then the decoupling parameter identification method was applied to the model,and parameters of transfer functions were identified using the ant colony algorithm. Furthermore,a phasor model of a hybrid offshore renewable energy conversion farm,consisting of wind,tidal,and wave turbines,was built in Matlab/ Simulink. With the model,the input and output data of the farm were acquired under the influences of wind,tidal,wave,and voltage disturbances. Finally,a transfer function model was built based on the collected data,and model parameters were identified. With the obtained parameters,the outputs of the equivalent model were calculated. The error between outputs of the equivalent model and the simulation model is very small,verifying the feasibility of the non-mechanism equivalent model in building the hybrid offshore renewable energy conversion farm.