A cam grinding method includes: a common base circle portion setting step of obtaining an angular range of a common surface based on first cam lift data of a first cam and second cam lift data of a second cam; a first cam grinding step of grinding the first cam; a second cam grinding step of grinding the second cam; and a common base circle portion traverse grinding step of, after the second cam grinding step, moving a grinding wheel in a traverse direction to perform spark-out of an unground part remaining at the boundary between the first and second cams.

A cam grinding method includes: a common base circle portion setting step of obtaining an angular range of a common surface based on first cam lift data of a first cam and second cam lift data of a second cam; a first cam grinding step of grinding the first cam; a second cam grinding step of grinding the second cam; and a common base circle portion traverse grinding step of, after the second cam grinding step, moving a grinding wheel in a traverse direction to perform spark-out of an unground part remaining at the boundary between the first and second cams.