A fixed-type looped network switch cabinet is provided with an airtight cabinet body. The cabinet body is inside divided into a bus chamber, a circuit breaker chamber, an isolation switch chamber and a cable chamber in sequence from top down by horizontal separation boards and a low voltage instrument chamber is mounted at the front side of the cabinet body. The switch cabinet provided by the invention is characterized in that a voltage releasing channel is arranged between a rear door of the cabinet body and the bus chamber, the circuit breaker chamber as well as the isolation switch chamber; a circuit breaker chamber voltage releasing board and an isolation switch chamber voltage releasing board are respectively arranged between the circuit breaker chamber and the voltage releasing channel and between the isolation switch chamber and the voltage releasing channel; the lower end of the voltage releasing channel is communicated with the cable chamber and a cable chamber voltage releasing board and a bus chamber voltage releasing board are arranged above the voltage releasing channel and the bus chamber respectively; the cable chamber voltage releasing board and the bus chamber voltage releasing board are both mounted on the cabinet tops. According to the invention, modularization of inner components of the cabinet body and miniaturization of the cabinet body are realized. Also, influence on other chambers when an accident occurs in one chamber is prevented and personal safety of workers outside the cabinet body is ensured.