The efficient manufacturing technologies greatly accelerate the development and production process. Optical components have higher precision requirements than mechanical parts. This provides great challenge for rapid manufacturing. Metallic optical system is featured high resolution, wide spectral range, light weight, compact design, low cost and short manufacturing period. Reflective mirrors and supporting structures can be made from the same material to improve athermal performance of the system. Common materials for metal mirrors in optical applications include aluminum, copper, beryllium, aluminum beryllium alloy and so on. Their physical characteristics and relative advantages are presented. Most kinds of metals have good machinability and can be manufactured by many kinds of producing methods. This makes metallic optical system saving 30%~60% cost and time than others. The manufacturing process of metal mirror is different due to its working spectral. The metal mirror can be directly manufactured by single point diamond turning. This is an outstanding technique in point of ultra-precision as well as economical manufacture of mirrors. The roughness values and form accuracy of optical surfaces after diamond turning can satisfy the quality level for applications in the near infrared and infrared range. And for visible light spectral the turning structures must be removed with a smoothing procedure in order to minimize the scatter losses. Some smoothing methods to obtain visible quality metal mirrors are given in this paper. Some new manufacturing technology, such as 3D printing, can be used for metallic optical system and several promising techniques are presented.