The invention discloses an unattended substation accumulator room fire-proof and explosion-proof device which comprises a gas detector, a gas detection controller, a trigger module, an alternating current contactor, a time switch, a fire disaster sensor, an and gate circuit, a fire extinguishing controller and an alternating current (AC) power supply. According to the device, a substation accumulator room can realize periodical exhaust with fixed time and fixed location and can realize automatic exhaust in time when encountering an explosive gas mixture, and automatic fire extinguishment can be timely realized when a fire breaks out in the accumulator room.