Injection molding is among the most widely used techniques for thermoplastics, and many complicated models are used in the mold enterprises. In the paper, the mold design flow by UG MoldWizard was analyzed. A mold for hair drier cover was successfully developed. How to search parting lines, create/edit parting surfaces, extract regions and create cavity and core were researched deeply. Best gate location analysis was studied by MoldFlow software, and a multi-cavity mold was designed. Angled-lift splits were developed to form the concave grooves. Lastly, the gating system and the cooling system were designed. It proved that MoldWizard can obviously improve the drafting efficiency and quality.