As the executive unit of the high-voltage circuit-breakers, the hydraulic mechanism of the circuit breaker is a key guarantee to the opening and closing operation. Therefore, reliable measurement and analysis of its switching speed characteristics are essential for evaluating the operating status of a high-voltage circuit-breaker. In this paper, we proposed the speed measurement principle and the standard process, use a high-voltage circuit breaker tester to carry out the speed testing on the hydraulic mechanisms of two types of high-voltage circuit breakers in Renhe Substation and Jiupan Substation, Chongqing, China. Then, through a cluster analysis method, the test results and failure cause of high-voltage circuit breakers in two substations are analyzed. The proposed standard process and analysis method can be a reliable reference for the characteristic test of high-voltage switches, which can provide reliable technical guidance schemes for the same type of tests.