This paper established 3D solid model of the electric sleeper bolt wrench core shaft by AN—SYS parametric design module.The core shaft diameter sections, load, stress and yield strength pa—rameters were set to obey a certain distribution of random variables, and according to the reliability of strength interference theory, the core shaft limit state equation was established using ANSYS/PDS module and with the LHS sampling method of Monte—carlo simulation technology, the paper analyzed the reliability of core shaft and gave the reliability and the random parameter sensitivity chan of core shaft, the change rule of the reliability with random variables was discussed.This study can provide theoretical basis for the design of electric sleeper bolt wrench core shaft, and has important signifi—cance for the reliability research of core shaft.