The utility model discloses a power distribution cabinet which includes a box body and a separation door hinged on the box body. An installation guiderail and a frame plate are installed in the box body. A flame retarding layer and a thermal insulating layer are sequentially attached on the inner side of the inner wall of the box body. A side face of the box body is provided with a fire extinguishing device which includes a thermal induction module, an alarm module, a solenoid valve and a fire extinguishing spray tank. The thermal induction module is connected with the alarm module and the solenoid valve. The solenoid valve is arranged on a fire extinguishing pipe of the fire extinguishing spray tank. The power distribution cabinet is capable of effectively preventing happening and spread of a fire disaster, and a heat radiation plate with an air fan is arranged at the bottommost part of the box body. Cold air is blown upwards from heat radiation holes of the heat radiation plate. Hot air is exhausted from vent holes at the upper part of the box body so that the temperature in the box body is reduced. If a fire disaster happens because the internal part of the box body is too hot, the thermal insulating layer and the flame retarding layer prevent further spread of fire flames.