The invention provides a vacuum circuit breaker which comprises a base plate, a high-voltage part arranged above the base plate, and a low-voltage control driving part arranged below the base plate, wherein the high-voltage part comprises an insulator and a high-voltage input end, a grounding end, a vacuum bubble and a high-voltage output end which are encapsulated in the insulator in a non-detaching manner. As the high-voltage input end, the grounding end and the high-voltage output end are encapsulated in the insulator in the non-detaching manner to form an integrated structure, the fault rate can be reduced; and meanwhile, the vacuum circuit breaker with a smaller size and a more compact structure is provided. The invention further provides an electric locomotive comprising the vacuum circuit breaker.