The invention discloses an infrared single-pixel imaging device and imaging method based on spatial light modulation. The imaging device comprises an integrated optical lens, a spatial light modulator, a collecting lens, a single-point light intensity detector, a synchronous control and data acquisition module and a processor, the spatial light modulator is arranged at a rear intercept position ofthe integrated optical lens, the collecting lens is arranged on an optical path of an output light of the spatial light modulator, the single-point light intensity detector is arranged on an opticalpath of the collecting lens, the data acquisition module is used for acquiring electric signals output by the single-point light intensity detector, and the processor is used for obtaining the electric signals acquired by the synchronous control and data acquisition module, performing inversion according to the electric signals, and obtaining a target pattern. According to the device and method, area array measurement of an infrared waveband can be realized by employing the single-point light intensity detector, the structure of the device is simple and compact, and the system cost is greatlyreduced.