Pinhole camera detection method and device based on double-light beam alternate emission

The invention discloses a pinhole camera detection method based on double-light beam alternate emission, which can effectively detect a pinhole camera hidden in a room and determine an accurate position of the pinhole camera; based on the characteristics that reflecting light is returned from an original path through a cat eye effect of the pinhole camera, and a divergence angle is smaller, a suspicious area where the pinhole camera possibly exists in the room is scanned by utilizing invisible two laser beams with a certain transverse interval, and two modulated lasers are controlled to alternately emit light and synchronize with a working time sequence of a CCD; the CCD performs inter-frame difference on adjacent frames of a sequence image in the acquired suspicious area to obtain an inter-frame difference image; as the adjacent two frame images obtained in the invention are active detection images, the difference of background reflected light is small, and the difference of reflectedlight of the pinhole cam