The invention discloses a comprehensive test method of a small satellite power subsystem. In the method, a solar cell array is replaced by a solar matrix simulator; a ground wired test and control platform of a satellite comprehensive test system is used to transmit wired instructions and collect important parameters; and ground test and control equipment, a remote measurement and control front end and a test computer are used to transmit remote control instructions and collect remote test data. After the satellite is electrified, the on operation time, off operation time and remote control command transmission time of the solar matrix simulator are reasonably controlled, the working state of a power subsystem is set, various parameters and states are monitored and interpreted, and thus, various test items are accomplished. In addition, a method of injecting normal or fault data blocks and program blocks is adopted to test the up injection function, reliability and fault tolerance are tested. The method has high test coverage, clear and definite flow, simple and reliable operation and convenient construction.