A rotor sheet, comprising a sheet body, the sheet body including eight groups of grooves for magnetic poles distributed symmetrically in a circumferential direction of the sheet body, wherein each among said groups of grooves comprises one first magnet groove , two second magnet grooves , two first air grooves and one second air groove ; the first magnet groove is symmetrical about a D-axis center line for installing a first magnet in the first magnet groove ; the two first air grooves are symmetrically distributed on outer sides of two ends of the first magnet groove ; first magnetic bridges are formed between the first air grooves and an excircle of the sheet body, and second magnetic bridges are formed between the first magnet groove and the first air grooves ; and the two second magnet grooves are symmetrically distributed in an approximate V shape about the D-axis center line for installing a second magnet in the two second magnet grooves respectively; the second air groove is positioned between ends of the two second magnet grooves near the side of the center of the sheet body; third magnetic bridges are formed between the excircle of the sheet body and the ends of the second magnet grooves near the outer circumference of the sheet body, and fourth magnetic bridges are formed between the second air groove and the ends of the second magnet grooves near the side of the center of the sheet body, characterized in that two rotor surface grooves are also formed in an outer circumference of the rotor sheet on the outer side of each among said groups of grooves, and the two rotor surface grooves are symmetrically distributed about the D-axis center line ; wherein an angle between a connecting line from a midpoint of each rotor surface groove to a central point of the sheet body and the D-axis center line ranges from 12.5° to 13°; and the rotor surface groove has a depth that is 0.4% to 0.6% of a radius of the sheet body, and a width that is 2% to 4% of the radius of the sheet body. the first magnet groove is symmetrical about a D-axis center line for installing a first magnet in the first magnet groove ; the two first air grooves are symmetrically distributed on outer sides of two ends of the first magnet groove ; first magnetic bridges are formed between the first air grooves and an excircle of the sheet body, and second magnetic bridges are formed between the first magnet groove and the first air grooves ; and the two second magnet grooves are symmetrically distributed in an approximate V shape about the D-axis center line for installing a second magnet in the two second magnet grooves respectively; the second air groove is positioned between ends of the two second magnet grooves near the side of the center of the sheet body; third magnetic bridges are formed between the excircle of the sheet body and the ends of the second magnet grooves near the outer circumference of the sheet body, and fourth magnetic bridges are formed between the second air groove and the ends of the second magnet grooves near the side of the center of the sheet body, characterized in that two rotor surface grooves are also formed in an outer circumference of the rotor sheet on the outer side of each among said groups of grooves, and the two rotor surface grooves are symmetrically distributed about the D-axis center line ; wherein an angle between a connecting line from a midpoint of each rotor surface groove to a central point of the sheet body and the D-axis center line ranges from 12.5° to 13°; and the rotor surface groove has a depth that is 0.4% to 0.6% of a radius of the sheet body, and a width that is 2% to 4% of the radius of the sheet body. <EOS>