The invention relates to a power-on starting self-test method of a flight control system, in particular to the power-on starting self-test method of the flight control system based on an XML technology. The method mainly comprises the steps of integrating codes of test items required by the flight control system PUBIT to a standard library, managing and calling the required PUBIT test items through the XML technology, generating a target code XML control file with the called PUBIT test items, and generating a target code matched with the flight control system base on the file. When a power-on starting self-test function of a new type is designed, compared with a prior hand-coding method, according to the power-on starting self-test method of the flight control system based on the XML technology, a code module is managed and called through the XML technology, the software reusability is improved, the software development and verification time is shortened, and the development efficiency is improved.