The invention relates to an UV (ultraviolet lamp ionization source)-FAIMS (high-field asymmetric waveform ion mobility spectrometry)-based quantitative detection method for volatile organic compound and belongs to the technical field of analysis and detection. According to the method, a flow velocity is changed, current signals are detected, and a standard product flow velocity-signal strength relation curve under a fixed concentration is obtained; a saturation flow velocity value corresponding to saturation signal strength is obtained according to the relation curve, and the small flow velocity region of the curve is intercepted, an ion composite loss coefficient is solved according to an ion composite equation; under a condition that a carrier gas flow velocity is larger than the saturation flow velocity, FAIMS analysis is carried out, so that a separation voltage-peak height relation curve is obtained, and the concentration mean value of a plurality of sets of samples is solved according to a quantitative model, so that quantitative analysis of a to-be-detected substance is realized. The quantitative detection method provides important reference for the ion mobility theory in the high-field asymmetric waveform ion mobility spectrometry and provides an important basis for promoting the expansion of the ion mobility spectrometry technology to more extensive quantitative analysis fields from qualitative analysis fields such as safety early warning and the like.