The utility model discloses a low-voltage alternating-current circuit breaker, which comprises a body, an operating mechanism, a fault triggering actuating mechanism, an electric energy storage mechanism, an intelligent controller, an insulation shell and a communication module. The body contains a movable contact and a static contact; the operating mechanism is mounted on the body and drives the movable contact and the static contact to contact with each other or to be separated from each other; the fault triggering actuating mechanism is mounted on the body and located on one side of the operating mechanism; the electric energy storage mechanism is mounted on the body and located on the other side of the operating mechanism; the intelligent controller is mounted on the fault triggering actuating mechanism and is connected with the fault triggering actuating mechanism; the insulation shell is mounted on the surface of the body; and the communication module is used for detecting status signals in the low-voltage actuating-current circuit breaker, can realize external communication output or display, and comprises a signal processing unit, a first communication port and a second communication port, wherein the first communication port is used for being communicated with an internal component of the circuit breaker, and the second communication port is used for being in information exchange with an upper computer or the intelligent controller. Various internal status signals in the circuit breaker can be diagnosed, and are output in a communication manner or are displayed via a self panel, and faults can be removed according to current statuses, and workload of a CPU (central processing unit) of the intelligent controller can be relieved.