The utility model discloses a system door and window mills special fixture, including base and supporting seat, the base top is provided with the supporting seat, supporting seat and base fixed connection, at supporting seat middle part fixedly connected with guide rail, the guide rail surface is provided with the slider, the slider can remove on the guide rail surface, the supporting seat both sides are provided with the second fixed block, second fixed block and supporting seat fixed connection, be provided with the screw rod on the second fixed block, the screw rod passes through the round pin hub connection with the second fixed block, the screw rod end is equipped with lock nut, fixed surface is connected with first fixed block on the supporting seat, it compresses tightly the pole to be provided with on the first fixed block. This kind of special fixture can be process before detects machined products's position accuracy, also can satisfy not unidimensional material milling process's requirement, reduces the manufacturing cost of enterprise, improves the product machining precision.