A manufacturing method of a rotor for a permanent magnet-excited, high-speed electric rotary machine according to the present invention comprises, covering an outer circumferential surface of at least one permanent magnet by a fiber-reinforced plastic protection cover with prestress compressing in radial direction; inserting a steel sleeve into the at least one permanent magnet to form a permanent magnet assembly; preparing at least one permanent magnet assembly; inserting a rotor shaft into the steel sleeve while applying hydraulic pressure to an inner circumferential surface of the steel sleeve of the prepared at least one permanent magnet assembly to expand the steel sleeve; and then removing the hydraulic pressure to tight fit the at least one permanent magnet assembly onto the rotor shaft.