Currently rail transit has no reliability qualification test standards yet. To verify whether the MTBF of LKJ meet the requirements, with the main working environment analysis of LKJ, comprehensive environmental conditions of six kinds of stress which consisted of temperature, humidity, vibration, shock, changes in voltage, surges and electrical fast burst were designed, and against the specific test conditions, the censored time trial statistics program was determined using. By experiment, MTBF point estimation value was obtained by 8 558 h, and 60% confidence interval estimate of the value was (2 858 h, 38 351 h).