Abstract: An air recycling device for auxiliary respiration apparatus has a casing, an air gather assembly, a valve assembly and a pressure switch unit. The casing has a regulator connector and an air feeder. The air gather assembly communicates with the casing. The valve assembly selectively blocks the communication either between the air feeder and the air gather assembly or between the regulator connector and the air feeder. In the moment between inhaling and exhaling, the pressure switch unit drives the valve assembly to block the communication between the air feeder and the regulator connector to gather the air expired from the user into the air gather assembly. When the user inhales again, the user inhales the air in the air gather assembly. The subsequently expired air flows through the regulator connector to a diving regulator. The air expired by the diver is recycled.