Method for controlling fuel cell vehicle

A method for controlling a fuel cell vehicle including a purge valve installed in a purge line through which an anode gas circulating in an anode is transferred to an aft discharge line through which humid air discharged from a cathode is discharged to outside, and an air pressure control valve installed in the air discharge line, the method comprising:

• setting, by a controller, a target purge degree of the anode gas of the purge valve and a target opening degree of the air pressure control valve;
• determining, by the controller, whether a fuel cell stack is in a power generation stop state;
• in response to determining that the fuel cell stack is in the power generation stop state, when the anode gas is purged from the anode based on the target purge degree and the target opening degree, determining, by the controller, whether hydrogen included in the anode gas will flow backwards to a stack enclosure connected to an upstream side of the air discharge line;
• and
• in response to determining that the hydrogen flows backwards, modifying, by the controller, at least one of the target purge degree and the target opening degree to a level at which the backflow of the hydrogen is prevented, and purging the anode gas from the anode based on the at least one of the modified target purge degree and the modified target opening degree.