The utility model discloses a transformer bolt spanner, including the arm of force no. 1 and the arm of force no. 2 that the symmetry set up, the one end of the arm of force no. 1 with the one end hinged joint of the arm of force no. 2, through -hole no. 1 is seted up to the arm of force no. 1, set up internal thread no. 1 in the through -hole no. 1, through -hole no. 2 is seted up to the arm of force no. 2, set up internal thread no. 2 in the through -hole no. 2, the direction of rotation of internal thread no. 1 and internal thread no. 2 is opposite, through -hole no. 1 and two in -connection lead screws of through -hole, the both ends of lead screw offer respectively with internal thread no. 1 and two assorted external screw threads of internal thread, set up the ratchet in the middle of the lead screw, the ratchet sets up ratched handle outward, recess no. 1 is seted up to the other end of the arm of force no. 1, swing joint locating plate no. 1 in the recess no. 1, recess no. 2 is seted up to the other end of the arm of force no. 2, swing joint locating plate no. 2 in the recess no. 2. The utility model discloses an arm of force no. 1 and the arm of force no. 2 that setting space can change are the utility model discloses be suitable for the not bolt of equidimension, in addition the utility model discloses the less job?requirements who satisfies narrow space of volume.