Abstract: The content of the fluid mechanics is dull and hard to understand. The traditional teaching lacks practice and the learning objective is ambiguous. The theory and practice are not synchronized, and lack of high-level objectives. To solve the problem of the student losing interest and motive force, "four lead-in" has been developed, e.g. leading in the flow phenomenon, applications of military, the scientific research and thoughts. The six steps of implement have been put forward, eg. setting the question, analysis, . The motive force and interest of the students have been improved and the teaching efficiency has been increased, through linking theory with practice, integrating the classroom and the battlefield.