The invention discloses a joint bearing inner sleeve outer spherical surface O-shaped oil groove machining device and machining method. The device is composed of a clamp main body, a three-jaw chuck,a positioning and pressing screw, a pressing nut, a balance block, a gland and a self-aligning pad, wherein the clamp main body is composed of a clamping disc and a clamping base plate, moreover, thetwo ends of the clamping disc and the two ends of the clamping base plate are perpendicularly connected, the connecting mode of the positioning and pressing screw and the clamping base plate is in transition fit, and the connecting mode of the self-aligning pad and the pressing screw is in transition fit. According to the joint bearing inner sleeve outer spherical surface O-shaped oil groove machining device and machining method, the operation is easy, three-jaw clamping automatic aligning is achieved, the production efficiency is improved by 6 times compared with that of an original device, the product superior product rate is up to 100%, the cutter loss is reduced by 70%, the production period is shortened, the production cost is reduced, and production and machining of the joint bearinginner sleeve outer spherical surface O-shaped oil groove are facilitated.