In order to solve the problem of 3D intricate product design and mold development, an approach based on UG NX was proposed. The design platform and modular technology of UG MoldWizard were introduced. How to add and edit attributes of the standard part library was explained by using sankyo lifter as example. As an application, a lamp set and its injection mold were rapidly designed by UG MoldWizard. How to patch surfaces, define parting lines and how to extract mold core and mold cavity were illustrated step by step. It proved that UG MoldWizard efficiently promoted work and integrated complex elements of design technology into automated sequences.