The utility model provides a box type transformers, include: casing, casing include side and shell roof, and the side has first ventilation hole, and the shell roof includes inclined plane and top surface, and the lower border on inclined plane is connected with the side, and the last border and the top surface on inclined plane are connected, are provided with second ventilation hole on the inclined plane. The technical scheme of the utility model the problem that the ventilation of having solved the box type transformers among the prior art effectively can not meet the demands.