In order to reduce strong transient thermal shock of high-temperature propellant gas in bore on the base fuze of projectile, unsteady heat conduction calculation method and finite element analysis of transient heat conduction were used, and the curve of the axial temperature distribution in the bottom fuze body was got.The results of simulation by ANSYS are consistent with the theoretical results.The results show that the temperature of base fuze is about 95 to 145 °C under normal firing.Thermal disturbance spreads in the fuze body less than 2 mm.The influence of propellant gas on the strength of base fuze can be ignored.Considering that projectile would be stranded in bore abnormally, when the fuze bodies were made by 50 steel or 35CrMnSiA steel, the influence of propellant gas on the strength of base fuze can be ignored, but when the fuze bodies were made by aluminium alloy such as 2A12, 7075, 7A04 or brass HPb59-4, the minimum thickness of fuze body should increase appropriately.