The utility model provides a dangerous gas monitoring device that leaks of reflective infrared laser industry of self -adaptation, it includes casing and the visual gun sight of setting above the casing, the laser red beam that collects that characterized by set up in addition in the casing is received and dispatched in the probe of an organic whole with laser infrared detection light beam, still includes electric servo cloud platform and control box, and the casing sets up in electric servo cloud bench, and probe and electric servo cloud platform and control box electricity are connected, still include corner reflector, corner reflector arranges the both ends of surveying the optical distance respectively in with the probe, an off axis parabolic mirror exiting light beam's chief ray is coaxial in corner reflector and the casing upper strata cavity.