Computer Operating System is a core basic course of computer science and technology specialty. It has many complex contents. The standardized teaching examination has been used in schools all the time, which is not suitable for the teaching mode of applied universities. Based on the application-oriented teaching mode, this paper analyzes the characteristics of practical teaching of Computer Operating System, discusses the shortcomings and shortcomings of standardized examination mode, explores the motivation, feasibility, methods and performance evaluation of the reform of non-standardized examination of Computer Operating System, and provides a new way of thinking for the examination of teaching in application-oriented universities under the new form.