Respond time is an important parameter for solenoid valve. For some kinds of switching solenoid valve, the respond time is very short and difficult to detect. In this paper, taking a typical hydraulic disc valve as an example it analyzes switching characteristic basing on the opening and closing oil pressure curve of the solenoid valve and gives the opening and closing time calculation method. According to these analyses, a useful time respond characteristic test system is introduced. The whole system design is simple, useful and effective. From the experiment result it can be seen that the system can give the oil pressure curve and respond time accurately.