Non-resonant photoacoustic detection device and detection method

The invention discloses a non-resonance photoacoustic detection device and a detection method. The device comprises a photoacoustic cell device, an infrared light source, a driving device, a plane reflection grating, a focusing optical system, a chopper, a photoelectric detector, a microphone, a gas distributor and a terminal device, the back surface of the plane reflection grating is fixed on an output shaft of the driving device, and the output shaft is parallel to the back surface of the plane reflection grating; the infrared light source emits mid-infrared incident light to the plane reflection grating, and the focusing optical system and the chopper are located on a light path of the incident light reflected by the plane reflection grating and guide the incident mid-infrared light into the photoacoustic cell device; the photoelectric detector is positioned at a light output port of the photoacoustic cell and is used for detecting a light intensity signal of the infrared light emitted from the photoacoust