Abstract: The development of an effective electromagnetic transient model for the wind turbine is the basis for the study of offshore wind power grid connection. In this paper, according to the models of the permanent magnetic synchronous generators (PMSG) provided by different manufacturers, a method of electromagnetic transient modeling of the PMSG based on the manufacturer's black box model is proposed. The model test data provided by the manufacturers are used to analyze the fault response characteristics of the fans, and the active and reactive power response expressions of different manufacturers under a voltage fault are derived, including the riding through control process during the fault and the transient switching in the intervals of different processes. The wind farm equivalent method of weighted average voltage dropping is proposed, and the full electromagnetic transient simulation software PSModel developed independently at home is used to model the full electromagnetic transient on an offshore wind farm in Guangdong province, China. According to the results of the steady state power flow and transient characteristics, the verification model is able to effectively realize the full electromagnetic transient modeling of an offshore wind farm through system testing, providing a research basis for the security and stability analysis of the wind farm after it is connected to the large power grid.