In order to guarantee the safety and reliability of software testing, according to the requirements of an embedded computer software system test, designed a system test method. The method introduce the situation of military and civilian embedded software test, and unit test case inside, and then from the platform hardware structure, software design, main function and its application effect, the design of the test platform is proposed. The research results show that the method communication protocol can be user defined, according to the test demand, and the method can be widely used. In accordance with the specification of the project, write test cases freely in the form of script, automatically collect test data, submit the test report, and give strong support and condition guarantee for the embedded computer software system test.