Theory of Practice is a philosophy that has been proved repeatedly by extremely successful practice and its basic ideas are widely applicable to the process of practical activities. Technical majors have a variety of practical teaching processes, they are common basic activities in students’ cognition, and students realize the leap from perceptual to rational knowledge through practical training. Students use the knowledge they have learned to counter-practice in society after graduation, to complete the second leap in cognition. At the same time the theory of practice has a good guiding significance for solving some problems and troubles in study and work.