The remote interface unit in the aviation electromechanical system is characterized by multiple types of signals, large number of icds and complex functions. For this the test software adopts modular design idea, based on LabWindows/CVI platform development, to store the hard line, bus management, test procedures and user management in a database, reduce the complexity of the application software, improve the software"s flexibility and maintainability. The automatic test process can be edited in the database, with good generality and high flexibility. The application proves this program meets the testing needs and has excellent performances in stability. It has been successfully applied to the field test of remote interface unit.