The utility model discloses a specialized tool for well testing preventer, including the cross lateral conduit, two flashboards, its symmetry sets up in lateral conduit both sides entrance, push awayfloodgate mechanism, its detachable connects lateral conduit's one end is kept away from to the flashboard, when its with it removes in lateral conduit to be used for promoting the flashboard behind the cross lock, and two baffles, including the central through hole, the central through hole is used for pushing away floodgate mechanism part and leans on at the baffle through supporting, wherein, set up a plurality of internal thread holes on the baffle on the same circumference, many screw rods, its both ends pass the corresponding screw hole in position on two baffles respectively, screw rodquantity is corresponding with internal thread hole count volume, wherein, the both ends connecting bolt of screw rod, as the direction swivel bolt who is close to to two baffles, the baffle pushes away floodgate mechanism and flashboard synchronous motion, makes the flashboard remove the other end to lateral conduit. The utility model discloses a specialized tool is convenient for install and ischanged the well testing preventer.