The present invention is a workpiece double-disc grinding method including supporting a sheet workpiece along a circumferential direction from an outer circumference side of the workpiece by a ring holder, and simultaneously grinding both surfaces of the workpiece supported by the ring holder with a pair of grinding wheels while rotating the ring holder, wherein the surfaces of the workpiece are simultaneously ground such that a wear amount of the grinding wheels per 1 μm of a grinding stock removal of the workpiece ranges from 0.10 μm to 0.33 μm. This workpiece double-disc grinding method can reduce nanotopography formed in previous steps such as a slicing step without degrading the flatness in the double-disc grinding step.