The invention discloses a method and a device for adjusting the rotating speed of a fan of a fuel cell. The rotating speed of the fan is adjusted according to the environmental parameters of the environment where the fuel cell is located, the current temperature of the fuel cell, the current rotating speed of the fan and the preset target temperature, wherein the environment parameters of the environment where the fuel cell is located, the current temperature of the fuel cell and the current rotating speed of the fan are considered, and the preset target temperature is also considered so thatthe rotating speed of the fan can be more accurately controlled, moreover, the heat dissipation speed of the fuel cell can be influenced by the size of the rotating speed of the fan, and then the temperature of the fuel cell can be influenced so that the accurate control over the temperature of the fuel cell can be realized.