Abstract: As a total leak rate detection technology for spacecraft, the flexible accumulation chamber leak detection technology is a kind of technology for the total leak rate detection for spacecraft. This new technology is based on the helium mass spectrum leak detection technology with a flexible material as the accumulation chamber. In this paper, the reliability of the key parts of the technology is analyzed and experiments are carried out. It is shown that the flexible accumulation chamber leak detection technology could meet the requirements of the total leak rate detection for spacecraft.