The use of freeform surfaces is increasing greatly in many fields, such as imaging, aerospace, illumination, biological engineering, and green energy, etc. And the polishing process of these surfaces are usually needed to obtain nanometer scale surface roughness, aiming to implement special functionalities and acquire high added value. This paper introduced the development of the two processes for the polishing of freeform surfaces, one is the serial-parallel hybrid machine based polishing using a self-developed ball-end flexible polishing tool, the other is the multi-jet polishing process. The design was presented in detail, and polishing experiments on plane and freeform surface were successfully implemented. As for multi-jet polishing, the process principle was presented at first. Material removal characteristics were demonstrated through a series of experiments, following with the discussion of application. And the experimental results prove that multi-jet polishing is effective to largely boost the polishing efficiency as compared to normal fluid jet polishing without degrading the surface quality, and also has the potential to extend the application field of fluid jet polishing to medium-large size freeform surfaces.