The invention relates to an RS trigger based on a GaAs-based low leakage current double cantilever beam switch NOR gate, which is composed of a DC bias source, a pull-up resistor, a GaAs-based low leakage current double cantilever beam switch HEMT (high electron mobility transistor), and is characterized in that two cantilever beams symmetrically designed above a grid electrode of the HEMT act as input ends of signals, each cantilever beam is provided with a pull-down electrode below, and each pull-down electrode is covered with an insulating silicon nitride dielectric layer. When the two input ends of the HEMT are low-level, both of the cantilever beams are located at a suspension state, a channel of the HEMT is blocked by a depletion layer, and output of a drain electrode is high-level; and when at least one input end is high-level, the cantilever beam corresponding to the high level is pulled down, and the channel of the HEMT is located at a conduction state, and the output of the drain electrode is low-level, thereby realizing a NOR gate logic function. Finally, the RS trigger is formed by two NOR circuits realized on the basis of the GaAs-based low leakage current double cantilever beam switch HEMT.