The utility model discloses a sweep automatically and look into device for detecting steel pipe tower joint welding seam, including the support, the support improve level set up one with steel pipe tower parallel arrangement's horizontal dead lever, the activity sets up a movable block on horizontal dead lever, it sets up a carriage release lever to move about on the movable block, the one end of carriage release lever sub -unit connection trace, the other end of trace is used for detecting the probe of steel pipe tower welding seam through the fixture centre gripping. The beneficial effects of the utility model are that: set up on horizontal dead lever through the movable block is movable, realized to drive through the position of adjusting the movable block removal of the position of popping one's head in to different welding seams, realize the regulation to the carriage release lever height through the knob, adapted to the steel pipe tower of different diameters, it is rotatory to drive whole device through the rotating electrical machines, has realized the automated inspection to steel pipe tower welding seam, has replaced artifical hand labour, and work efficiency is high.