In traditional offshore wind turbine model tests， it is difficult to reproduce the turbulent wind loads in the laboratory. And the space limitation of the laboratory site makes it impossible to carry out large-scale offshore wind turbine model tests. The scale contradiction between the upper wind turbine and the lower platform cannot deeply study the full coupling mechanism of the offshore wind turbine. With the improvement of computing power and the breakthrough of key problems such as numerical integration algorithm and control， the above contradiction can be solved by the real-time hybrid test method. This paper takes the 5 MW fixed offshore wind turbine of the National Renewable Energy Laboratory （NREL） as the research object and makes the physical substructure model according to the scale of 1∶90. AeroDyn program is developed as the numerical substructure， UDP / IP communication mechanism is added as the data acquisition and transmission mode， and the push rod actuator is taken as the loading device to build a complete real-time hybrid test system so as to carry out the real-time hybrid model test of fixed offshore wind turbine under no wave condition. The test results are compared with these of FAST software. The good agreement shows the feasibility of the real-time hybrid model test method， which provides a reference for the further development of the real-time hybrid model test technology of offshore wind turbines， and provides technical support for the structural design and safe operation of the offshore wind