As the characteristics of high strength,light quality and easy formability,metal-polymer composite parts are receiving increasing attention in the field of aerospace,automotive manufacturing and communications. The molding process of metal-polymer composites with injection method and microstructures is introduced,and a numerical model for the polymer melt filling into the microstructures of metal surface is established. The flow front of the melt on the metal surface is tracked by using level set method,the influences of the microstructure size,the injection speed and the metal surface temperature on the filling ability of the melt into the microstructures are studied as well. The experimental apparatus for the metal-polymer composites molding technology is constructed,and microstructures of the metal surface are obtained by using sand blasting method. Accordingly,the specimens of the metal-polymer are molded successfully. Through tensile shearing test,the simulation results are verified. Results obtained in this paper have an important inspiration and guidance to optimize the molding parameter sand improve the part quality of the new metal-polymer molding technology.