A test method for testing a solar power generation system is provided. The solar power generation system includes a DC to AC converter and a control unit. The DC to AC converter is electrically coupled between an external power grid and a solar panel. The control unit is configured to control the DC to AC converter to switch between a power generation mode and a test mode. When in the power generation mode, a photoelectric energy generated by the solar panel is provided to the external power grid via the DC to AC converter. When in the test mode, the control unit controls the DC to AC converter to generate a testing electrical energy by obtaining from the external power grid, to effect a test result of the solar panel when the testing electrical energy passes through the solar panel.