The purpose of digital design of marine integrated electric propulsion system is to provide a digital design platform for the system and determine the digital model of the system and the corresponding digital processing method. Because the traditional ship design method is not suitable for the design of ship integrated electric propulsion system, the existing design research only focuses on a single field and does not form a complete digital design system, which leads to the system design is very difficult and even easy to take many detours. This paper discusses several key problems that must be solved in the process of realizing digital design of the system, and studies the digital design technology of the system from four aspects: digital design architecture, system modeling and simulation, control strategy design and reconfiguration.