The invention discloses a PCSC shear joint structure of a plate girder overall assembly type composite beam bridge. A steel beam is provided with a longitudinal side baffle. A precast concrete bridgechannel plate is located behind the steel beam and is located on the top of the longitudinal side baffle. A longitudinal perfusion space is formed between the precast concrete bridge channel plate andthe steel beam. The precast concrete bridge channel plate is fixedly connected with the steel beam by using a shear joint structure in a longitudinal perfusion mode between the precast concrete bridge channel plate and the steel beam. According to the PCSC shear joint structure of the plate girder overall assembly type composite beam bridge, by using pressure perfusion, a longitudinal perfusion space is formed and the longitudinal perfusion space is combined with concrete to form steel-concrete composite beams, and then all the steel-concrete composite beams are pushed to the corresponding bridge piers to be in position in the longitudinal direction, and assembly type combination of an overall precast concrete bridge channel plate unit and an overall steel beam unit is achieved. An assembly type industrialization bridge construction method that the steel-concrete composite beams are constructed in a factory and the fact that all the steel-concrete composite beams are pushed to the corresponding bridge piers to be in position in the longitudinal direction can be achieved. All the advantages of the PCSC shear joint structure are achieved. The three problems of the high working amount of welding on a site, extremely high accuracy requirements of adaptation of manufacture and poor fatigue resistance of inconel weld are overcome.