A constraint abrasive flow ultra-precision machining device comprises a polishing tool head, a feeding apparatus, a recovery pedestal and a motion executing mechanism; in the polishing tool head, a sheath is sleeved on the installation step of a nozzle, the nozzle is fixedly connected with a polishing head tube socket, springs are sleeved on the nozzle and tightly compress the sheath, the cooperation surface of the sheath and the nozzle is provided with sealing grooves, the sheath is prepared through using an elastic material insensitive to abrasive wear, the center of the nozzle is punched to form a through hole, a channel for the flow-in of an abrasive flow is arranged in the polishing head tube socket, the polishing head tube socket is fixed on an installation plate, a laser displacement sensor is fixed at one side of the polishing head tube socket, and the installation plate is connected with the motion executing mechanism; and the center of the recovery pedestal is a boss for installing a workpiece, the periphery of the boss is provided with an abrasive flow recovery slot, the periphery of the recovery slot is provided with a ring-shaped abrasive flow baffle plate, the abrasive flow baffle is higher than the upper surface of the workpiece, and an abrasive flow recovery outlet is arranged in the recovery slot. The device has the advantages of high precision, high machining efficiency, small damage and low cost.