The invention discloses a hydrogen control system of a hydrogen fuel cell automobile. The hydrogen control system comprises a hydrogen inlet pressure sensor, an air inlet pressure sensor, a hydrogen spraying solenoid valve group and a system controller, wherein the hydrogen spraying solenoid valve group is used for introducing hydrogen to a positive inlet of a fuel cell stack module, the hydrogeninlet pressure sensor is arranged in a pipeline introducing the hydrogen into the positive inlet and is arranged between the hydrogen spraying solenoid valve group and the positive inlet, the air inlet pressure sensor is arranged in a pipeline introducing air into a negative electrode of the fuel cell stack module, and the system controller is connected with the hydrogen inlet pressure sensor, theair inlet pressure sensor and the hydrogen spraying solenoid valve group and is used for calculating pressure difference according to a first pressure signal sent from the hydrogen inlet pressure sensor and a second pressure signal sent from the air inlet pressure sensor and controlling and adjusting the opening frequency of the hydrogen spraying solenoid valve group according to the pressure different. The hydrogen demand quantity is adjusted in real time according to the pressure difference so as to form closed-loop control, the hydrogen control accuracy is improved, and the hydrogen utilization rate is improved.