The invention provides a method of manufacturing a low-power-consumption hydrogen sensor based on two-dimensional electron gas. The hydrogen sensor includes a two-dimensional electron gas membrane for detecting H2; a heater is used for maintaining the heating temperature of the two-dimensional electron gas membrane; when the sensor is exposed to a H2 atmosphere, the conductivity of the two-dimensional electron gas membrane is increased, and according to the change on current before and after the detection, the concentration of H2 in the atmosphere is acquired. The sensitivity of the sensor can be enhanced by means of the temperature (200-400 DEG C) of the two-dimensional electron gas membrane. In the invention, the two-dimensional electron gas membrane can be suspended in air by supporting the membrane just on several leading-out beams, so that heat from the heater is basically used for maintaining the temperature of the membrane and can only be transmitted to a silicon substrate through the leading-out beams, so that the temperature of the silicon substrate is increased not quite so much. The sensor greatly increases utilization rate of heat and achieves low power consumption during work.