Mould manufacturing involves a large number of groove, slot, hole, prism, pyramid and narrow special-shaped surface called structural surface. Such particularity of these structural surface has caused restrict to the exposure between the grinding, polishing electrode tools and the covered processing surface. So General polishing machining can not be used for such precision surface processing. At present, In mould field, the requirement of the structural surface increasingly need high quality, For example, precision injection mould, not only the die face of the injection mould but the injection mould shoot also has high roughness demands. As the structural surface machining is difficult to use contact-machining tools (such as polishing or grinding), even if the manual operation is also very difficult (because manual operation also needs the auxiliary tools).So the precision processing of the mould structural surface has become an urgent unresolved problem. But now it still lack of intensive research. In order to solve the problem, we raise a new tool-free principle based on the liquid-solid two phase abrasive flow machining.