Due to the high reliability demand in the high density aerospace tracking and control mission, system test of mission software is high repeatability, great workload, low testing efficiency and reliability. Through analyzing the system testing condition and testing demand, a software automatic test system based on black-box testing is designed. This article introduces the automatic test system including system structure, main function modules, testing platform disposition and testing workflow. Several key technologies are expounded such as test case management, test data automatic generation, test process control, test result evaluation and test report automatic creation. This test system can effectually reduce the manual repeat workload, improve the automatization of system testing, and enhance the system testing efficiency and quality.