Abstract: Traditional maintenance of low-voltage frame circuit breakers requires power interruption on the user side, compromising power supply reliability and forcing long-term reliance on a reactive maintenance model where repairs substitute for proactive upkeep. Despite efforts to minimize outage durations, customer power interruptions remain unavoidable. To address this, this paper proposes a live replacement method for frame circuit breakers based on same-source bypass technology. This method centers on bypass operation techniques, utilizing the low-voltage same-source busbar as the bypass power point. It is supported by a hardware system comprising specially developed dedicated load transfer devices and rapid bypass connection apparatus. Validation tests confirm that this approach achieves zero-outage perception on the user side during maintenance and replacement operations, offering a novel solution for live maintenance of low-voltage circuit breakers in distribution substations.