Different from the traditional mold design methods based on experience,intuition or repeared mold testing,this article conducts injection mold design optimizarion by a combination of the computer-aided design software UG,the data conversion software CAD Doctor and the limited element analytical software MoldFlow.By testing such indicators as formation pressure,injection time and maximum clamping force,this paper reveals that the density of grid division can ont serve as the standard for the accuracy of the plastic mold analysis,by simulating the filling,cooling and warping in the injection process,this paper obtains the optimal design parameters for casting and cooling systems and the distribution features of air pochets,weld lines and warpages ,etc,and provides improtant refernce for mold structural design optimization.Finally,this article proves in practice that the CAD/CAE techniology-based injection molds are flexible and reliable and able to meet quality requirements.The mold design procedures of this case can serve as reference for fraternity.