The utility model discloses a circuit breaker with seal insulating housing, including operating mechanism, still include confined insulating housing, insulating housing fixes on the operating mechanism case, sets up insulating pull rod in insulating housing's the enclosure space, insulating pull rod is fixed in the mechanism of operating mechanism incasement, vacuum interrupter and mutual -inductor are fixed respectively to the both ends of insulating pull rod, lead wire direct entry operating mechanism incasement portion in insulating housing of mutual -inductor, the terminal outgoing lines that advances of circuit breaker fixes the both sides at insulating housing respectively, set up the full skirt between terminal outgoing lines in advancing of insulating housing, the outside at insulating housing and operating mechanism case coupling part also sets up the full skirt. The utility model has the advantages that: it is small, light in weight, the box adopts insulating material, and business turn over line direct mount in the insulation box body outside need not especially to do insulating the processing, shorten the business turn over linear distance greatly, because the box is insulating, the mutual -inductor directly waters and adorns in the box. Especially insulating the processing need not done to the mutual -inductor lead wire inside the box.