Air inlet system of auxiliary power device and auxiliary power device

The invention relates to an air intake system of an auxiliary power plant, comprising: an air intake damper attached to a fuselage of an aircraft and rotatable between a damper open position and a damper closed position; the air inlet channel is arranged at the downstream of the air inlet air door so as to guide air entering through the air inlet air door to an air inlet component of the auxiliary power device; the separation channel is arranged in front of the air inlet air door along a fuselage of the aircraft and can move between a separation channel opening position and a separation channel closing position; the cooling pipe is arranged at the downstream of the separation channel so as to guide air entering through the separation channel to a cooling component of the auxiliary power device; and the actuating device is attached to the air inlet air door and the separation channel so as to control opening and closing of the air inlet air door and the separation channel. By arranging the separation channel,