The invention discloses a non-contact gesture recognition method and system. The system comprises a signal emitting receiving module, an injection phase-locked quadrature receiver module and a gesture recognition module. According to the method and the system, the signal emitting receiving module emits wireless signals to a tested object, the injection phase-locked quadrature receiver module locks the phases of the wireless signals and conducts quadrature demodulation to echo signals and the locked wireless signals to output first baseband signals obtained from in-phase demodulation and second baseband signals obtained from orthogonal branch demodulation. The gesture recognition module determines the movement direction of the tested object based on the magnitude variation of the first and second baseband signals. Therefore, the non-contact gesture recognition is achieved. The system need neither cameras nor complicated algorithms, the cost is reduced, and the application scope is wide.