The invention discloses an extrusion forming feeding device for wood plastic wallboards. The extrusion forming feeding device comprises a lifting device, an open feed hopper, a transparent conveying pipe, a tee material distribution box and a PLC control device, wherein the tee material distribution box comprises an inlet end, a first outlet end and a second outlet end; material distribution plates are arranged in the first outlet end and the second outlet end; the first outlet end and the second outlet end are connected with a drying box and a stirring box respectively; the material distribution plates are hinged to the inlet end of the tee material distribution box through rotating shafts, and the first outlet end or the second outlet end can be right covered; a stirring device is arranged in the transparent conveying pipe; a humidity sensor is arranged on the side, close to the tee material distribution box, of the stirring device; the drying box conveys a material into the stirring box through a conveying pipe; an assistant adder is arranged on the stirring box; and the PLC control device is connected with the humidity sensor, a baffle plate power source and a metering device. According to the feeding device, it is guaranteed that all parameters conform to the processing requirement before wood plastic is subjected to extrusion or injection molding.