Abstract: To deal with the gun barrel life problem caused by transient thermal shock during successive firing under complicated firing regulations, a mathematical model of one-dimensional transient heat transfer for gun barrel was established. Firstly, finite difference schemes of internal nodes and boundary nodes based on energy balance method and ADI (alternating difference implicit) scheme were derived. Secondly, taking the barrel of some 5.8 mm rifle as the study object, the temperature distribution of gun barrel during 150 successive firing rounds was solved by programming on the basis of the numerical results of classical interior ballistic trajectory. Finally, the temperature of gun barrel outside wall was measured by the thermal infrared imager, and the numerical results are consistent well with the experimental results, which demonstrates the validity of the established model and the algorithm used under complicated firing regulations.