The invention relates to a lead outlet end positioning apparatus. The lead outlet end positioning apparatus comprises a supporting plate, a positioning mark post and fixing structures, wherein the positioning mark post is arranged in the middle position of the supporting plate; and the fixing structures used for fixing the supporting plate on a transformer clamp are arranged at the two ends of the supporting plate respectively. According to the lead outlet end positioning apparatus, by virtue of two first strip-shaped holes in the supporting plate and two insulating thread rods at the end parts of the positioning mark post, the sliding connection between the positioning mark post and the supporting plate are realized; a lead weight is arranged on each of the supporting plate and the positioning mark post, and the lead weight on the positioning mark post is used for positioning the clamp in a vertical direction; the horizontal direction of the clamp can be positioned rapidly and accurately through the lead weight on the horizontal side of the supporting plate by reading a datum point on a drawing; in addition, relatively high positioning precision, convenience in use, and time saving and labor saving are achieved; and the lead outlet end positioning apparatus can be widely applied in the fields of lead outlet end positioning and assembling of a power transformer, an electric reactor and a current conversion transformer.