As the digital twin technology is more and more widely used in power system equipment planning, construction, operation and other life cycle management process. At present, in the actual application process, the power grid digital twin model has some problems, such as high modeling cost, long time, low efficiency, and difficulty in meeting the needs of operation and maintenance maintenance of the three-dimensional model of digital transfer of infrastructure, which hinder the in-depth application of digital twin technology in the whole life cycle management and control of power grid equipment. This paper presents a 3D parametric modeling method and system based on substation engineering design drawings. Through a series of methods such as standardized processing of engineering design data, automatic extraction of modeling elements, and model parameterization construction, a standard substation model that can be repeated in the whole life cycle of power grid equipment management and control is finally generated. This method effectively reduces the modeling cost and improves the modeling efficiency.