The invention relates to a machine tool for machining jaws of bench vices. The machine tool for machining jaws of bench vices comprises a tool body, a fixed installing seat, a feed mechanism, a stand column and a main shaft, wherein a cushion block is tightly clamped between a fixed vice body and a movable vice body, two end faces of the cushion block, respectively tightly pressed against the jaw end face of the fixed vice body and the jaw end face of the movable vice body, are parallel to each other, one end part of the main shaft can be fixed on the stand column in a rotating way, a first end-face milling tool, a second end-face milling tool and a cushion sleeve are coaxially fixed at the other end part of the main shaft, the second end-face milling tool is parallel to the first end-face milling tool, and the cushion sleeve is arranged between the first end-face milling tool and the second end-face milling tool. According to the invention, when a jaw of a bench vice is machined, the machining of jaw installing grooves is performed in the last step of bench vice machining, and two jaw installing grooves are completely machined once through a pair of parallel end-face milling tools, so that cumulative errors are avoided, and the parallelism of a pair of installing grooves is precisely controlled more easily, thereby improving the occlusion performance of bench vices in the process of clamping workpieces.