The invention discloses a combined impeller. At least one impeller is arranged in an annular seat body, wherein the annular seat body is provided with a guide surface and is also provided with at least one annular body hole group, the annular body hole group comprises a plurality of concave clamping grooves and a concave annular body hole, and each clamping groove is communicated with the annularbody hole and the guide surface; and the impeller is provided with an annular body which is embedded into the annular body hole of the annular seat body, a plurality of blades encircle the periphery of the annular body, reinforcing sheets for connecting the annular body and the blades are arranged between the inner edges of the blades and the periphery of the annular body, the reinforcing sheets are correspondingly embedded into the clamping grooves, the inner edges of the blades and the guide surface have the same shape and are matched, and air passages are formed between the two adjacent blades and in a section formed by the annular seat body. Through the design, the weak sections formed between the annular body and the blades can be eliminated, so the impeller is not easy to deform, andaccurate positioning and combination between the impeller and the annular seat body are favorable.