Rear door assembly follow-up U-shaped container and dumper

The invention belongs to the technical field of dump trucks, and particularly relates to a rear door assembly follow-up U-shaped container and a dump truck. The rear door assembly is arranged at the tail ends of a bottom plate assembly and side plate assemblies, and the rear plate assembly is attached to the tail ends of the bottom plate assembly and the two side plate assemblies; the two connecting arms are arranged on the upper edges of the two sides of the rear plate assembly respectively and connected with the rear plate assembly through L-shaped first reinforcing plates respectively, and the middles of the connecting arms are correspondingly hinged to the side plate assemblies. The two connecting support arms are used for correspondingly connecting the connecting arm and the rear plate assembly respectively, and the connecting support arms are connected with the rear plate assembly through L-shaped second reinforcing plates; the two fixing seats are arranged on the two sides of the bottom plate assembly