The invention disclose an oiling machine oil gun return-gas regulating device, which is provided with an air regulating chamber arranged on a return-air passage of an oil gun; the air regulating chamber is internally provided with an air regulation valve provided with a push rod, the push rod is connected with a switch bar of the oil gun in a continuous action way, the air regulating chamber is provided with at least one air regulating mouth, the air regulation valve can regulate an air port of the air regulating mouth at the air regulating mouth of the air regulating chamber to slide in size, a regulating element which regulates the size of the air port is arranged on the air regulating mouth of the air regulating chamber and can be an adjustable ring or an air pipe with a regulation valve. The oiling machine oil gun return-gas regulating device is applicable to the regulation of the oil gas recovery on the oil gun of the oiling machine, has novel structure, flexible control, good oil saving and environment protection effects, guarantees the safety of a gas station and an oil tank.