Abstract: Disclosed is an extrusion mold for tire treads that extrudes semi-finished tires, for example, a cap tread, a wing tread and a sub tread. The preformer includes a first preformer die-holder having a wing tread flow-path, a cap tread flow-path and a sub tread flow-path formed therein, a second preformer die-holder, and a final die inserted into the second preformer die-holder and ejecting an extrudate. The improvement of the preformer die includes a middle upper preformer die and a middle lower preformer die between the first and second preformer die-holders to be brought into contact with the final die. The middle upper preformer die is formed with a wing tread-connecting guide groove and a cap tread-connecting guide groove communicating with the wing tread flow-path and the cap tread flow-path, respectively. The middle lower preformer die is formed with a sub tread-connecting guide groove communicating with the sub tread flow-path.