The invention relates to an air-tight cabin air filling and air tightness detecting device comprising an air-filled pipeline and a suction pipeline which are selectively connected with an air-filled space of an air-tight cabin by a pipeline switching element, wherein the input end of the air-filled pipeline is connected with an air-filled bottle, and the output end of the suction pipeline is provided with a vacuum pump; a filter, an air-filled valve and a vacuum pressure gauge are sequentially arranged on the air-filling pipeline along the air intake direction, and then the air-filling pipeline is connected into a switching element, and the air inlet end of the air-filled pipeline is also provided with a first self-locking connector; a suction valve, a vacuum meter and a vacuum pump are sequentially arranged on the suction pipeline along the suction direction; and the air inlet of the vacuum pump is provided with a second self-locking connector by a one-way valve. In the air-tight cabin air-filled and air tightness detecting device, a structure that the suction and air filling are combined is adopted, the suction and air-filling processes of the air-tight cabin are carried out uninterruptedly and alternatively, air filling is carried out after suction is carried out, the purity can reach requirement, the speed is rapid and the suction and air-filling efficiency is high.