Abstract: Aiming at the problems of traditional bypass switches in 0.4 kV low-voltage distribution network operation and maintenance, such as large volume, heavy weight, cumbersome installation, and poor adaptability to single-phase operation scenarios, a design scheme of a 0.4 kV quick-installation miniaturized single-phase bypass switch is proposed. This scheme adopts the technical path of "modular design and intelligent monitoring" to complete the development of modules including miniaturization, lightweight, quick-installation structure, and intelligent monitoring. The switch is suitable for low-voltage single-phase live working and provides a new solution for live-line work in low-voltage distribution networks.