Abstract: Not only it is important to impart knowledge, it is more important to improve students' creativity and comprehensive quality during fluid dynamics teaching.In this paper four "unity" is discussed,which includes the unity of hydrostatics and hydrodynamics teaching,the unity of fluid pressure on the plane and the surface, the unity of theory and practice and the unity of this course and specialty. The following view is put forward.To make students establish philosophical thought, to improve their abilities of solving practical problem by computer, to teach some relevant prospective professional knowledge are very important.