Control method based on backup power system of fuel cell

The invention discloses a control method based on a backup power system of a fuel cell, which comprises the following steps that: 1) the state of an external power supply is judged through detecting two parameters of the backup power system, i.e. battery current and bus voltage; 2) when the external power supply is detected to be power-off, the battery pack in the backup power system powers up external electric equipment, the fuel cell system in the backup power system is promptly prepared to be started, and the time to start the fuel cell system is determined according to the magnitude of the discharge current of the battery; and 3) when the fuel cell system is needed, the power output to the external electric equipment is controlled through regulating the rotating speed of the fan in the fuel cell system. Therefore, each functional module of the backup power system with the fuel cell system as the core can organically and efficiently operate, thereby improving the efficiency.