The invention discloses a pre-buried shear key connector box for a precast facade panel and a machining method of the pre-buried shear key connector box. The pre-buried shear key connector box comprises an upper top plate, a lower bottom plate, a box body and a connecting strand, wherein a strand penetrating hole is formed in the lower bottom plate; the box body is formed by arranging three lateral plates in a surrounding manner; the connecting strand penetrates through the strand penetrating hole; the side, where no lateral plate is arranged, of the box body is an open side; the upper top plate is inclined to the outer side of the box body; the two side plates adjacent to the open side and the lower bottom plate are inclined to the inner side of the box body; the two side plates are arranged to form ribs; the pre-buried pin of the connecting strand is pre-buried in the precast facade panel; after treated with concrete placement, the pre-buried shear key connector box, a floor and a beam together form a shear connector. The pre-buried shear key connector box has the advantages that the structure is simple; the manufacture is easy; standard batch production on a trolley can be realized; the quality is controllable; pollution and material waste are avoided; the production efficiency is high; the transportation, loading, construction and exterior wall decoration are convenient; the shear and vibration resistance of a building main body is improved.