Abstract: Along with the development of the software engineering technique, Software testing becomes more and more important during the development process and it is very important to software’s quality. On the other hand, automated testing becomes more and more prevalent in software testing. In this paper, after studying the test of USB interface software and analyzing the demand of automation, the scope for USB automated testing is established. Then test flow charts are built based on the demand and scope. We inherit component mode of software development and finish developing automated testing system for USB interface software automated testing, which is realized on Microsoft Visual Studio.Net platform. Using this system the efficiency of the test is much more improved.