A method of controlling power of the fuel cell vehicle includes dividing an expected driving path of the fuel cell vehicle into a plurality of sections and setting the plurality of sections according to a gradient, and comparing whether a predicted battery state of charge variation is within a battery charging/discharging allowance range for each of the plurality of divided sections The method further includes comparing predicted power with a predetermined maximum allowance power for each of the plurality of divided sections, and setting the plurality of divided sections as a battery charging/discharging prohibition section and a battery charging/discharging allowance section in advance according to a result of the comparison of the predicted battery state of charge variation and the predicted power.