A power tool packing apparatus provides a packing force to form a compact coupling between an application tool and an output shaft of a power tool. The packing apparatus comprises a pressing disk, a crank set, a movable wheel and a plurality of steel balls. The movable wheel and the pressing disk form a space between them to hold the steel balls. The crank set has a plurality of pins butting the steel balls. The pressing disk has a force applying surface butted by the steel balls in regular conditions so that the pressing disk provides a packing force butted outward in the regular conditions. The movable wheel has retraction notches. When the movable wheel is turned, the steel balls slide into the retraction notches to provide the pressing disk an inward retraction space, thereby the packing force is released and the application tool can be disassembled quickly.