Vacuum circuit breaker for high-altitude railway vehicle

The invention discloses a vacuum circuit breaker for a high-altitude railway vehicle, which comprises an upper insulator, a lower insulator, a supporting insulator, a steering flange, a base, a grounding switch and an operating handle, and internal structure key components comprise a vacuum tube, a steering mechanism, a transmission rod, a driving cylinder, an electromagnetic valve, an air storage cylinder and the like. The steering mechanism equivalently converts thrust and displacement in the vertical direction and thrust and displacement in the horizontal direction, driving steering is achieved, a lower insulator and a supporting insulator jointly support an upper insulator which is horizontally installed, and the electrical distance meets the technical requirement for application of a railway locomotive in a high-altitude area. Compared with an upper insulator vertical type vacuum circuit breaker, the overall height and the gravity center of the vacuum circuit breaker are reduced, and the operation reliab