The invention discloses a double-head multifunctional box cover plastic extruding machine which is applied to the field of plastic extruding machines and solves the technical problems that the mold replacement time is long, and the manual input is large. According to the technical scheme, the double-head multifunctional box cover plastic extruding machine comprises a rack, a feeding hopper arranged on the rack and a cylinder, a plurality of square first molds are vertically arranged on the rack in a coplanar manner, and the cylinder is detachably connected with the second molds matched with the first molds; a connecting shaft is horizontally welded at the butt joint positions of the multiple first molds, connects the multiple molds into a whole and is rotationally connected to the rack, and the cylinder is connected to the rack in a sliding manner in a direction perpendicular to the first molds. The double-head multifunctional box cover plastic extruding machine has the technical effect that the multiple first molds are rapidly replaced in a rotating manner, so that the mold replacement time is shortened, and the production efficiency is improved.