Disclosed is an RC load-based island-prevention protection apparatus for a zone area photovoltaic grid-connection inverter. The island-prevention protection apparatus comprises a detection unit, a calculation unit and a capacitance resistance cabinet; the input end of the detection unit is connected with the secondary side of a transformer; the output end of the detection unit is connected with the calculation unit; and one end of the capacitance resistance cabinet is connected with the secondary side of the transformer while the other end of the capacitance resistance cabinet is connected with the calculation unit. By improving the existing reactive compensation capacitance resistance cabinet, the capacitance resistance cabinet can be used in a reactive compensation mode in a normal condition; and if it is detected that the zone area is in an island state, the reactive compensation function is stopped immediately, and a switching capacitor and resistor disturbance island-prevention logic judgment state enters. The island-prevention protection apparatus, used as an external disturbance source, can be combined with the island prevention protection function of the inverter, so that automatic machine halt of the inverter in an island condition can be realized.