Prefabricated box girder inner mold core

The utility model discloses an inner mold core of a prefabricated box girder, which is used for solving the problem that the appearance quality of the prefabricated box girder is poor due to the fact that a splicing seam of an existing inner mold core is not compact. The prefabricated box girder inner mold core is composed of four mold piece assemblies and telescopic supporting rods, and is characterized in that an upper mold piece assembly and a lower mold piece assembly are adjustably supported through the multiple sets of telescopic supporting rods, and a left mold piece assembly and a right mold piece assembly are supported through the multiple sets of telescopic supporting rods; the matching surfaces between the templates in the upper and lower mold sheet assemblies and the templates in the left and right mold sheet assemblies are inclined surfaces, and the upper and lower mold sheet assemblies are combined to form a trapezoidal notch space expanding from inside to outside. The opposite formworks are sup