Micromold manufacturing technology is very important for the mass production of micro parts. In this paper, modeling of micromold is established in 3D software firstly. The 3D modeling is input into machining simulation software Master CAM to simulate machining process. The machining parameters and cutting tool path are optimized in machining simulation. Machining G code of micromold obtained from post-process program of Master CAM is input into HMI system of Micro Machine Tool (MMT), and hence the micromold will be machined precisely in MMT.