To meet the requirements of reliability and efficiency for digital substation, this paper presents a practical digital substation design scheme, including substation communication network design, substation configuration design and device design. The scheme uses not only redundant communication technology based on PRP (parallel redundancy protocol) and HSR (high-availability seamless ring), but also flexibility hardware and software configuration of devices and whole station type configuration from system to device.The presented design is not only reliable and efficient, bust also convenient for maintenance and expansion of digital substation.