The safety and reliability of fuse are the decisive factors,which guarantee whether the targets are destroyed accurately or the rate of accidental explosion is reduced during storage,transportation,and handling.The structure model of fuse explosive train was determined and reasonably simplified on the basis of typical medium and large caliber munitions.To observe the reaction state,a related finite element model about fuse explosive train in actual charge condition was established with Lagrange elements by AUTODYN.For modeling of air and donor charge(TNT),the Euler elements were utilized.The JWL parameters were used for TNT and the identical ignition and growth reaction rate parameters were set for JH-14C booster with 1.65 g/cm3.The fluid-solid coupling method was applied to fuse explosive train on the condition of sympathetic detonation.Through adjusting the distances between TNT and fuse,the pressure histories was analyzed in the reaction of the JH-14C explosive train in fuse,and the two critical distances of sympathetic detonation and safety were gained for the fuse explosive train.The results show that the critical sympathetic detonation distance is 23mm and the corresponding incident pressure is 5.4GPa; the safety distance is 760mm and the corresponding incident pressure is 2.5e-4GPa.The results of this study provide useful information to ensure the reliability and safety of fuse as well as avoid unnecessary explosive accidents in the modern weapon system.