The invention discloses a spiral axial-flow type oil-gas multiphase pump impeller. The spiral axial-flow type oil-gas multiphase pump impeller comprises a hub and a plurality of groups of spiral axial-flow type blades arranged on the hub, wherein the groups of blades are symmetric along the surface of the periphery of the hub and are perpendicular to the surface; each group of blades are provided with secondary blades; the secondary blades are sheet structures; the sheet structures are perpendicularly fixed on the surfaces of the blades; the secondary blades have cambered-surface sheet structures or planar sheet structures; one end of each secondary blade is positioned at the top end of the outer periphery of the corresponding blade; and flow channels with gradually changed radiuses are formed on the surfaces of the secondary blades and the surface of the periphery of the hub. The secondary blades are arranged on the spiral axial-flow type blades; the areas of the flow channels are changed by the secondary blades, so that mixed fluids are mixed uniformly; and according to difference of the revolving speed of an impeller and the flow of the fluids, the shapes and the quantities of the secondary blades can be various, and the thicknesses of the secondary blades are changed non-uniformly to meet requirements of different environments, conditions and fluids.