The utility model discloses an exhaust structure of an alternating currentcircuit breaker, which relates to the field of circuit breakers and comprises a shell and an arc extinguish chamber, the shell comprises a middle cover, a left cover and a right cover, the left cover and the right cover are mounted on two sides of the middle cover, and the middle cover is provided with a plurality of first gas guide plates for guiding gas from the arc extinguish chamber to the left side and the right side. The middle cover and the left cover are matched to form a first exhaust channel, the middle cover and the right cover are matched to form a second exhaust channel, a third exhaust channel and a fourth exhaust channel, and a first outlet communicated with the first channel and a second outlet communicated with the second exhaust channel and the fourth exhaust channel are formed in the bottom of the side wall of the shell. And a third outlet communicated with the third channel is formed in the upper surface of the shell. The utility model has the advantages of space saving and good safety.