Portable hydrogen and nitrogen replacement device for vehicle-mounted hydrogen system

The invention relates to a portable vehicle-mounted hydrogen system hydrogen and nitrogen replacement device which comprises a hydrogen system controller, the hydrogen system controller is provided with a power interface, a hydrogen and nitrogen replacement interface and a communication interface, the hydrogen system controller is further connected with a hydrogen and nitrogen replacement module, a cylinder valve and a main pressure reducing valve, the cylinder valve is arranged on a hydrogen cylinder, and the main pressure reducing valve is arranged on the hydrogen cylinder. The main pressure reducing valve is arranged on a pressure relief pipeline of the hydrogen cylinder; the hydrogen system controller is further connected with a pressure detection module, the pressure detection module is located in the hydrogen cylinder, and the pressure detection module transmits collected pressure data in the hydrogen cylinder to the hydrogen system controller; the hydrogen system controller is also connected with a pro