The utility model relates to a perimeter warning light path adjustment device, especially one kind is used for the perimeter warning optic system reference adjusting device in when debugging. The transmitting terminal includes support and sight, slide rail, and the support is parallel to each other with perpendicular to the ground's laser emitter installation shell, and the slide rail is installedon the support perpendicularly to be parallel to each other with the central line of sight, the doubling of frequency piece is arranged in on the slide rail, the receiving terminal is provided with and is in the target spot on the same straight line with the sight central line, and this target spot to receiving terminal sensor distance is the same to the laser emitter width between centers with the sight central line. The utility model discloses a fix the slide rail on laser beam, utilize sight central line and adjustment jackscrew to aim at the receiving terminal window with the slide rail,doubling of frequency piece reciprocating motion in the slide rail, according to facula position on the doubling of frequency piece, can be fast, accurate completion light path adjustment.