A hydrogen reforming system is provided and includes a steam reforming system, a dry reforming system, and a water supply device. The steam reforming system is configured to (i) receive a raw material gas and react the raw material gas with water to generate a first mixed gas containing hydrogen and carbon monoxide, (ii) react the first mixed gas with the water to generate hydrogen and carbon dioxide, and (iii) discharge hydrogen and carbon dioxide. The dry reforming system is configured to (i) receive and react the raw material gas and the carbon dioxide discharged from the steam reforming system to generate a second mixed gas containing hydrogen, (ii) react the second mixed gas with the water to generate hydrogen and carbon dioxide, and (iii) discharge hydrogen and carbon dioxide. The water supply device is configured to supply the water to the steam reforming system and the dry reforming system.