The invention relates to a safety electrical leakage
circuit breaker. The safety electrical leakage
circuit breaker comprises a
circuit breaker shell and a
handle and also comprises a test button, wiring terminals and protection covers, wherein the circuit breaker shell comprises an operation shell, a rectangular concave shell, a spring cavity and a wiring cavity, the test button comprises a button body and a locking device, the locking device comprises a sliding way, a front sliding hole, a locking strip, a shift strip and a limitation strip, the wiring terminals are arranged in pairs, at least two pairs of wiring terminals are arranged, and each wiring terminal comprises a fixed terminal, a U-shaped sliding terminal, a driving bolt and a misplug-preventing plate, a pair of protection covers are arranged, and each protection cover comprises a front plate, a basic-layer plate, a high-layer plate, a wire through hole and an arc
front cover. The invention also discloses an application method for protecting the safety electrical leakage circuit breaker. By the safety electrical leakage circuit breaker, misplug during plug of a wire can be prevented, the driving bolts of the wiring terminals and a
metal core of the wire can be coated to prevent
electrical shock, a test electrical leakage loop can be locked in a conduction state, and the
handle is prevented from being operated by mistake.