The utility model discloses a remove detecting device and system. Wherein, should remove detecting device includes: laser scanner for scanning gets into the object of warning region, and is scanning the entering send alarm signal during the object of warning region, audible -visual annunciator, with laser scanner is connected, is used for receiving send acousto -optic warning behind the alarm signal. The utility model provides a current removal detection technology technical problem that uses the wrong report that causes in open job site and fail to report.