A rotor for a brushless electric machine, having: a rotor core; a rotor shaft, installed inside the rotor core; multiple U-shaped holes are formed in the rotor core, each of the U-shaped holes including a first magnet installation hole, a second magnet installation hole and a hardening material filling hole formed by a bottom space of the U-shaped hole. A groove structure is formed on the rotor core forming a first surface of the hardening material filling hole, with the width of a groove opening of the groove structure being smaller than the width of the bottom of the groove. The rotor for a brushless electric machine provided in the present invention has the advantages of low internal magnetic circuit losses and a stable mechanical structure.