Abstract: The depressurization and repressurization test of electronic instrument is a key technique in the development of a manned spacecraft system. This paper presents the modification scheme for the devices of the depressurization and repressurization test. Based on the depressurization design analysis and the repressurization design analysis, the modified devices are made to satisfy the two categories of technical requirements, which is verified by experimental studies. It is shown through the debugging test that the modified devices can meet the relevant technical requirements, which can ensure the smooth operation of the depressurization and repressurization test.