The invention relates to a method for testing the grid connection performance of a wind-solar combined power generation system. The method comprises the steps of 1, determining test points of field detection for the wind-solar combined power generation system; 2, determining test conditions of field detection for the wind-solar combined power generation system; 3, determining the test content of field detection for the wind-solar combined power generation system; and 4, testing the performance of grid connection points of the wind-solar combined power generation system. The technical scheme provided by the invention solves a problem of field detection for the power generation system in grid connection performance, and has very important significance for improving the standardization and the accuracy of the field test for the wind-solar combined power generation system.