In view of the system failure caused by the increase of contact bounce time of a certain type of microswitch, an ac.celerated simulation of the marine atmospheric environmental effect consisting of a dry-wet alternating acidic salt spray testand a damp heat test is designed. The microswitch with the same model of the field fault part is selected as the research ob.ject, and the fault phenomenon is successfully reproduced through the accelerated simulation test in the laboratory. Com.bined with the test results, the influence mechanism of corrosive environment, electric ablation and other factors on the in.crease of contact bounce time is analyzed.