In order to solve the problems such as inconvenient operation in nitrogen charging and replacement process, and difficult to accurately control the nitrogen pressure in the maintenance of barrel ammunition, and to meet the requirements of nitrogen charging and replacement operation in remote and harsh environments, an intelligent nitrogen charging device for barrel ammunition based on PLC control system is designed, which has the characteristics of independent work, vibration resistance, intelligence, easy transportation and convenient charging and charging. The application results show that the device improves the working efficiency and quality of barrel ammunition maintenance. It meets the requirements of nitrogen filling and replacement operation for barrel bombs in remote and harsh environment, and can continue to work without commercial power. At the same time, it realizes manual and automatic working modes and signal prompts such as overpressure and air leakage alarm. At present, the device has been equipped with several types of cartridge for cartridge maintenance in remote environmental areas.