Hydraulic system is consists of mechanical, hydraulic and electrical devices. Therefore, hydraulic system malfunction are a lot of types. Based on the complexity and all-around of hydraulic system malfunction, it is very difficult to solve the hydraulic system malfunction. Hence how to quickly and accurately identify the mechanical is the forefront of current research projects. With the rapid development of computer communication technology, computer-aided diagnosis technology can solve the problem of fault diagnosis of hydraulic systems. In order to solve the hydraulic station mechanical, according to the existing hydraulic system failure analysis, it makes visual dynamic diagnosis. In this paper, the visual dynamic diagnostic technology is introduced, which works in the technical feasibility and tastes its convenience and practicality in the actual practice.