The invention discloses a machining method of a turntable bearing of a beer filling machine. The machining method comprises the following steps: firstly, machining a ball blocking block and an inner ring ball blocking block matching hole according to the preparation clearance of 0.03-0.05mm between the ball blocking block and the inner ring ball blocking block matching hole, as well as a conical pin, wherein the ball blocking block and the conical pin need to be disassembled and assembled repeatedly for twice, so as to check whether the ball blocking block can be reset by virtue of the conical pin; secondly, roughly grinding to machine the medium-frequency quenched channel, wherein a machining margin of 0.1-0.15mm is remained after rough grinding; and checking whether the rigidity of the channel is qualified; thirdly, carrying out fine grinding with small tool feeding to machine the channel; demagnetizing and cleaning the disassembled ball blocking block and the conical pin after the channel is finished; and assembling according to marks. Compared with a traditional machining method, the requirement of the clearance between the ball blocking block and the ball blocking block matching hole and the machining processes of each part are added; the quality requirement of a product is guaranteed; the noise problem of a finished turntable bearing product is avoided and the foundation for eliminating noise quality problem when the turntable bearing is machined is laid.