Prefabricated box girder formwork system and construction method

The invention relates to a prefabricated box girder formwork system and a construction method. The construction method comprises the steps of prefabricated box girder pedestal construction, integral adjustable side frame installation, reinforcement cage binding, end formwork installation, prefabricated box girder pouring, inner formwork removal and integral adjustable side frame removal. The integral adjustable side frames are arranged on the two sides of the prefabricated box girder, the integral adjustable side frames are connected through the opposite-pull screws, the formwork erecting construction efficiency of the prefabricated component is improved by applying the prefabricated component, and the end formworks, the integral adjustable side frames and the inner formworks are fixed through bolts; the lug plates welded on the diaphragm plate formwork are fixed with the integral adjustable side frame through bolts, so that the formwork erecting construction efficiency is improved, related components can be