The utility model provides a bearing wire winding's elasticity instrument, does include that half ARC end portion of half arc spanner, I, half arc spanner, II, half arc spanners II is connected with the handle of half arc spanner I is articulated, is provided with 2 on the inner arc of semicircle spanner I 5 is individual internal tooth provided with 2 on the inner arc of semicircle spanner II 5 individual internal tooth, tooth's socket on internal tooth and the bearing wire winding lock nut excircle cooperatees. A damage, can also improve work efficiency simultaneously that bearing wire winding's elasticity instrument is used for bearing wire winding's dish to change the elasticity specially, utilize that the manpower just can relax with the wire winding pretension on the bearing box, replace the crane to be under construction, prevent the emergence and the lock nut of incident.