Novel small-size circuit breaker

The invention discloses a novel small-size circuit breaker. The novel small-size circuit breaker comprises a shell and a tripping mechanism, wherein the tripping mechanism is arranged in the shell, an installation structure comprises a left clamping piece and a right clamping piece, sliding holes are formed in positions, opposite to the left clamping piece and the right clamping piece, of one side of the shell, the left clamping piece and the right clamping piece are respectively slide in the sliding holes, a push assembly is arranged in the shell, is coupled to a wiring terminal and is also in linkage with the left clamping piece and the right clamping piece so that the left clamping piece and the right clamping piece are ejected out when a fault occurs in the circuit breaker, and magnets are arranged on the left clamping piece and the right clamping piece and are used for absorbing an external circuit breaker installation bar. In the novel small-size circuit breaker disclosed by the invention, the circuit b