In order to improve the physical, chemical and mechanical properties of metal-ceramic composite materials, some micro-alloying elements have usually been added, but due to some different adding methods or some improper subsequent processing methods, the efficacy of micro-alloying elements can not fully play, and even some negative effects have been caused. Ultimately the above results can be attributed to the precise controlling of micro-alloying elements. Cemented carbide is one of the most important materials in metal-ceramic composite materials. Therefore, in this paper, effects of micro-alloying elements on the preparation, microstructure and properties of cemented carbides have been detailedly summarized. The sources of micro-alloying elements, their action mechanisms in cemented carbide, and their precise controlling difficulties have been analyzed and studied. Based on their action mechanisms in cemented carbide, some possible effective measures are proposed to precisely control the content, phase composition, existence state, distribution etc., in cemented carbide. And some theoretical assistances can been guided to the actual production of cemented carbide.