Abstract: The p ractical p roperties of p lastic mould are expounded and a few surface - treatment techniques are introduced. A se2 ries of experiments shows that electroless p lating nickel is quite effective technological in that it has high hardness and is excep tionally corrosion - resistant, that the temperature of powder nitriding, compared with that of pack boriding, is lower, hence, powder nitriding does not affect internal structure of steel and treating effect is better and that the pack boriding can contribute to high hardness layer but the corresponding technology p roblems are difficult to be solved. This paper discusses the characteristics and app lication range of these techniques, points out that pack boriding technology has p roblem and puts forward the correspoinding solution