The invention provides a dual-stage enhanced photoacoustic spectroscopy detector device and a detection method thereof. According to the sequential orientation of photoacoustic spectroscopy analysis,the dual-stage enhanced photoacoustic spectroscopy detector device includes a pulsed infrared light source, an analytical gas chamber and a photoacoustic light chamber in order. The gas outlet of theanalytical gas chamber is connected with a pressure stabilizing system, the gas inlet of the analytical gas chamber is connected with a circulating gas pump and a continuous negative pressure degassing device in sequence, and a light filtering wheel is disposed between the analytical gas chamber and the photoacoustic light chamber; a plurality of light filtering pieces are uniformly distributed along the circumferential direction on the light filtering wheel; the dual-stage enhanced photoacoustic spectroscopy detector device is also provided with a communication module and a data processing module, the analytical gas chamber and the photoacoustic light chamber are in signal connection with the data processing module, and the pulsed infrared light source, the analytical gas chamber, the light filtering wheel, the photoacoustic light chamber, the circulating gas pump, the continuous negative pressure degassing device and the data processing module are respectively in data transmission connection with the communication module, and are in data transmission connection with a master station computer through the communication module.