A grinding and polishing combined machining machine tool relates to a precision grinder and a polishing machine tool. The grinding and polishing combined machining machine tool comprises a grinding device, a polishing device, a movable on-line trimming device and a workbench device; the grinding device and the polishing device are respectively arranged on one side of the workbench device; the grinding device is provided with a grinding device tool body base, a Z1-axis servo motor, a Z1-axis ball screw pair, a Z1-axis guide rail, a Y1-axis servo motor, a Y1-axis ball screw pair, a Y1-axis guide rail, a grinding device column, a spindle carrier and a grinding wheel; the polishing device is provided with a polishing device tool body base, a Z2-axis servo motor, a Z2-axis ball screw pair, a Z2-axis guide rail, a Y2-axis servo motor, a Y2-axis ball screw pair, a Y2-axis guide rail, a polishing device column, a polishing device suspension arm and an air bag grinding head; the movable on-line trimming device is provided with a trimmer, an X2-axis guide rail, an X2-axis cylinder and a rotary platform; and the workbench device is provided with a workbench, a workbench tool body, an X-axis guide rail, an X-axis ball screw pair and an X-axis servo motor.