Abstract: The stratosphere airship moves in the near space environment,radiated by the sun,the temperature of envelope changes a lot,as a result,the penetrability of He changes a lot.The penetrability of He influences the lifetime of the stratosphere airship.This article,analyses the connection of the temperature and the penetrability.The results,such as the shape of airship,the range of pressure and the average penetrability have been showed after numerical calculation,meanwhile,the lifetime of the airship is calculated according to the conditions above.