The invention provides a setting die of an extrusion die for a door and window covered edge PVC wood-plastic sectional material. The setting die comprises an upper template, a box strip, a lower template and a cavity. A plurality of cooling water holes and air holes are formed in the periphery of the cavity. The cavity is an inverted-V-shaped cavity which is defined by the upper template, the box strip and the lower template together, the top corner of the cavity is set in a 90-degree mode, inclined planes on the two sides of the upper portion of the cavity are set to be arc-shaped surfaces which arch in an inclined upward mode, and strip-shaped ribs which inwards protrude are arranged on the tail portions of the two ends of the cavity. The setting die is simple in structure, can effectively fill a downward concave portion of a formed product and overcome the defect that the formed product is downwards concave, and is mainly used in the mode of being matched with the corresponding extrusion die.