The utility model provides a metal framework for casting a metal and nonmetal composite impeller. The metal framework comprises a bottom plate and an upper cover, and the bottom plate and the upper cover are connected through blades arranged between the bottom plate and the upper cover. The blades are provided with through holes which are evenly distributed in an array mode from the rear ends of the blades to the front ends of the blades and from the sides, making contact with the bottom plate, of the blades to the sides, making contact with the upper cover, of the blades, and the interval between every two adjacent through holes is 3-5 cm. The through holes formed in the bottom plate are located in the 1/2 positions between the combination positions of the adjacent blades and the bottom plate, and the interval between the adjacent through holes ranges from 3 cm to 5 cm. The through holes formed in the upper cover are located between the combination positions of the adjacent blades andthe upper cover. After the non-metal layer is poured, a net-shaped structure can be formed by means of the through holes to wrap the metal framework, the combination effect is enhanced, meanwhile, the distance between the through holes is controlled within a certain range, and the situation that the strength of the framework is reduced due to excessively dense through holes is avoided.