The invention discloses an evaporation sealing chamber, which comprises a passageway cabin body and a sealed cabin body arranged inside the passageway cabin body, wherein a test cabin is arranged in the sealed cabin body, an internal circulation air duct is formed between the sealed cabin body and the test cabin, the internal circulation air duct is communicated with the test cabin, the sealed cabin body is provided with a fresh air intake pipe and an exhaust gas discharge pipe, the fresh air intake pipe is provided with a fresh air intake valve, the exhaust gas discharge pipe is provided withan exhaust valve, an external air bag is arranged outside the sealed cabin body and/or an internal air bag is arranged inside the sealed cabin body, the external air bag is connected with a first external air bag pipeline, the first external air bag pipeline is provided with a first external air bag valve, the internal air bag is connected with an internal air bag pipeline, and the internal air bag pipeline is provided with an internal air bag valve. The evaporation sealing chamber can compensates for the indoor gas by means of the external air bag and the internal air bag, and can avoid thesituation of inaccurate gas detection data because the indoor gas is contaminated since the outdoor gas enters the indoor under the action of a gas pressure difference and is mixed with the indoor gas.