Fuel cell shutdown purging method, device and system

The invention belongs to the technical field of fuel cells, and particularly relates to a fuel cell shutdown purging method, device and system. The method comprises the following steps: firstly, after a fuel cell system is shut down, obtaining theoretical water quantity generated in the working process of a fuel cell; then continuously blowing the fuel cell, carrying out gas-liquid separation on the blown gas, and collecting the actual water amount brought out by blowing; and finally, comparing the theoretical water volume with the actual water volume, and stopping purging until the actual water volume is increased to the theoretical water volume. According to the invention, the purging time can be effectively controlled, the purging time is prevented from being too long or too short, a good storage environment is provided for the fuel cell, and the reduction of the service life of the fuel cell is avoided. The purging time is effectively controlled, the purging time is prevented from being too long or too sh