The invention discloses a load test method for the power-driven start-up of an offshore wind power project. At present, how to do a load test during the power-driven start-up of an offshore booster station is a technical problem that is urgently needed to be solved by the technical personnel in the art. When a wind power generating set is in a safe stop state, a unit-side converter is locked, a grid-side converter acts as a reactive power compensator, the reactive power emitted or absorbed by the converters is adjusted according to test requirements. By controlling the power of each converterand the number of invested converters, the amplitude of output current can be flexibly controlled, the requirements of a power-driven start-up test of the offshore booster station are satisfied, and the complete set of calibration of primary equipment, a secondary circuit, a metering instrument and a relay protection and automation equipment can be realized. The power-driven start-up test of the offshore booster station is achieved before the grid-connection of the wind power generating set, the content of the power-driven start-up test of the offshore wind power project is improved, the risksof a later set grid-connected test are reduced, the debugging quality is improved, and the trial run time is shortened.