The utility model provides an automatic switch electric power marks tablet, its alternating current power supply passes through the wire and connects the light sense detector respectively, the microprocesso, mark the tablet switch, the light sense detector, the microprocesso, it connects gradually to mark tablet switch passing signal line, it connects isolator respectively through the wire and marks the tablet to mark the tablet switch, the circuit breaker marks the tablet, the terminal box marks the tablet, current transformer marks the tablet, voltage transformer marks the tablet, earthing knife -switch marks the tablet, main transformer marks the tablet, the condenser marks the tablet. Beneficial effect: automatic switch electric power marks tablet has the illumination function, made the power operating personnel can see electric power clearly at night and mark the tablet, and the tablet switch was marked in automatic closed or disconnection night, daytime, and is novel in design, practical.