The invention discloses a rotor structure which includes an impeller and a rotation shaft, wherein the impeller includes a first impeller (2) and a second impeller (7); the first impeller (2) comprises a first hub front section (40), a first hub rear section (4), and a first projecting step part (5); the second impeller (7) comprises a second hub front section (6), a second hub rear section (11), and a second projecting step part (10); the outer diameter of the first hub rear section (4) is less than that of the second hub front section (6), the outer diameter of the second hub front section (6) is less than that of the second hub front section (6), the outer diameter of the second hub front section (6) is less than that of the second hub rear section (11), and the outer diameter of the second hub rear section (11) is less than that of a third shaft section (9); the first projecting step part (5) of the first impeller (2) is inserted into a groove part which is located in the second impeller (7) and matched with the first projecting step part (5); the second projecting step part (10) of the second impeller (7) is inserted into a groove part which is located in the third shaft section (9) and matched with the second projecting step part (10). The rotor structure can effectively increase the lift and improve the performance and efficiency of products.