The invention discloses an integrated insert rear floor, a vehicle body and a manufacturing method of the integrated insert rear floor. The integrated insert rear floor comprises an aluminum
alloy die-cast rear floor body and a plurality of steel inserts pre-embedded in the aluminum
alloy die-cast rear floor body, and the connecting edges of the steel inserts and the rear floor body are filled with molten aluminum to form
interlocking. The steel inserts comprise various connecting beams, wheel cover reinforcing pieces and front floor connecting inserts. During manufacturing, the steel insert is placed in a die for high-pressure die-
casting of aluminum
alloy. The vehicle body comprises the integrated insert rear floor and a lower vehicle body front structure, and the front floor connecting insert of the rear floor is welded to the lower vehicle body front steel structure. By embedding the steel insert, the connection problem of the floor and the steel vehicle body after
die casting is solved, a large number of steel-aluminum connection points are omitted, the influence on an existing
production line is small, and the integration level, precision and rigidity are improved.