In photovoltaic (PV) power generation systems, the DC side circuit operates under continuous high-voltage live conditions all year round, serving as a critical link for safe operation, maintenance, and fault protection of power stations. The DC PV disconnector is a specialized electromechanical switching device designed exclusively for PV DC systems. It is primarily installed between PV module arrays, junction boxes, and inverters, acting as an indispensable fundamental safety component of PV systems. Unlike circuit breakers and fuses that focus on fault protection, it takesphysical isolation as its core function, while integrating circuit switching, safety protection, and system operation and maintenance. It is widely applied in residential PV systems, commercial and industrial distributed PV plants, large-scale ground-mounted PV power stations, and solar-energy storage integrated systems. This article comprehensively elaborates on its core functions, current isolation performance, mainstream types, key selection criteria, and practical application scenarios.