A continuous-generation gear grinding method of conducting a gear grinding process such that while a thread-shaped grinding wheel is rotated around an axial center thereof and fed in an axial center direction, a position coming into contact with abrasive grains is constantly changed in the presence of a water-soluble grinding fluid by performing a grinding feed in a direction parallel to an axial center of a gear blank and by serially rotating the gear blank around the axial center, the grinding wheel being a vitrified grinding wheel having abrasive grains bonded by a vitrified bond with pores formed among the abrasive grains, and the abrasive grains having a grain size of F120 to F180.