This paper introduced the definition of digital design in substations，as well as its importance and necessity. And the application of digital design in Lhasa ±400 kV converter station was described in details. We improved the efficiency and quality of design by digital design, as well as preliminarily implemented the flow design and corporation between different majors during the engineering digital design process based on the digital design platform. The effect of digital design was showed through the numerical handover in Lhasa converter station project.