The utility model relates to a precast beam construction technical field, concretely relates to gooseneck is fixed to pretensioned prestressing, the power distribution box comprises a box body, the box alternates the rectangle box of passageway for seting up, and the passageway that alternates runs through two plane of symmetries of box perpendicularly, still be equipped with the connecting plate that is used for strengthening fixed gooseneck intensity in the box, the connecting plate is fixed in on the box inner wall. This fixed gooseneck is directed against when adopting newly -designed pre -tensioning system precast beam pedestal, uses fixed gooseneck, and the fixed gooseneck of newly designing must have higher intensity and rigidity, is difficult to the characteristics of deformation, also has great improvement on the stretch -draw tonnage.