The mixed mismatched conical worm drive, which is easy to process, is proposed in this paper. The worm drive consists of a conical worm ground by a discoid conical grinding wheel and a conical worm gear processed by an Archimedes conical hob. The ease of processing for the worm drive is due to the fact that the Archimedes conical hob is easier to manufacture compared to the hob used in existing standard mismatched conical worm drives. The meshing theory is established for the mixed mismatched conical worm drive, and systems of nonlinear equations are deduced to determine its contact points. The numerical results demonstrate that the geometric and kinematic meshing properties of the conical worm drive, including the mixed and standard mismatched versions, are excellent and comparable. Compared to the standard mismatch, the worm drive is more insensitive to assembling errors after the mixed mismatch. Therefore, the mixed mismatch has advantages over the standard mismatch for a conical worm drive.