The invention discloses a non-dispersive infrared light gas detection system adopting an electric pulse infrared light modulation method, so as to reduce power consumption at the part where infrared light is modulated, and stability is improved; an internal coating method is adopted in structural design of a gas chamber, so that infrared light diffusion and external disturbance are reduced further, and gas detection accuracy is improved; a calibrating circuit is used for signal processing, so that different collected gas can be detected accurately through calibration; a programmable logic device is adopted to calibrate different environmental factors in air through software collection, the functions of data teletransmission, abnormity warning and the like are achieved through FPGA treatment, thereby improving module detection precision, timeliness and stability and reducing system cost simultaneously. The non-dispersive gas detection system disclosed by the invention has the advantages that the system is small in volume and low in power consumption, continuity and timeliness of gas detection can be achieved, and the detection precision is improved greatly.