A stationary fixture for machining of an aluminum alloy wheel, the fixture being composed of a machine tool base, a support I, a rotary joint, an end cover I, nuts, a power shaft I, bearings, an end cover II, an L-shaped plate I, airtight mechanisms, a power chuck, clamping jaws, a wheel, L-shaped plate II, an end cover III, a decelerator I, a power shaft II, a servo motor I, an end cover IV, a support II, a coupling, a decelerator II, a servo motor II, a positioning column, a hydraulic cylinder I, a base, a movable plate, pressure blocks, positioning plates, wherein the support I and the support II are mounted on the machine tool base by bolts, the power shaft I is mounted inside a bearing seat at the upper end of the support I, a group of bearings is mounted between the bearing seat and the power shaft I, the end cover I is mounted on the left side of the bearing seat at the upper end of the support I by screws, the end cover II is fixed to the right side of the bearing seat at the upper end of the support I by screws, the L-shaped plate I is mounted on the power shaft I by screws, and the rotary joint is mounted at the left end of the power shaft I; the decelerator I is mounted inside the support seat at the upper end of the support II, the servo motor I is mounted at the right end of the decelerator I, the end cover IV is mounted at the right end of the support seat at the upper end of the support II by screws, the end cover III is mounted at the left end of the support seat at the upper end of the support II, the power shaft II is mounted at the output end of the decelerator I, and the L-shaped plate II is mounted on the power shaft II by screws; the base is mounted on the L-shaped plate I and the L-shaped plate II by screws, the hydraulic cylinder I is mounted on the base via the positioning column and screws, the power chuck is mounted on the hydraulic cylinder I, a group of clamping jaws is mounted on the power chuck, the output end of the servo motor II is mounted on the input end of the decelerator II, the two groups of airtight mechanisms are mounted on the movable plate, the four positioning plates are mounted on the movable plate, the L-shaped plate I is provided with a plurality of oil passages, the oil passages pass through the power shaft I and are connected with a hydraulic source via the rotary joint, characterised in that the fixture is further composed of a sealing ring I, a sealing ring II, a support plate I, a linear single-axis robot, a support plate II, a connecting plate, a dynamic friction plate, a static friction plate, a lip rubber sealing ring, hydraulic cylinders II, guide rails, a guide rail I and a guide rail II, in that a nut is mounted at the left end of each bearing to position the inner ring of the bearing, the sealing ring I is mounted between the end cover I and the power shaft I, the sealing ring II is mounted between the end cover II and the power shaft I, the dynamic friction plate is mounted on the L-shaped plate I, the static friction plate and the lip rubber sealing ring are mounted at the right end of the support I, the lip rubber sealing ring is connected with an oil passage inside the support I, the support plate II is mounted on the base by screws, the linear single-axis robot penetrates through the base and is mounted on the support plate II, the output end of the decelerator II is mounted on the output shaft of the linear single-axis robot via the connecting plate and the coupling, the support plate I is simultaneously mounted on a slider of the linear single-axis robot and the movable plate, the four guide rails are mounted and fixed on the movable plate, the four groups of hydraulic cylinders II are mounted on the guide rails, and the pressure blocks are mounted at the output ends of the hydraulic cylinders II, an oil passage is processed at the upper end of the support I, and the hydraulic cylinder I and the hydraulic cylinders II are connected to the oil passages on the L-shaped plate I via joints and oil pipes.