An islanding detection system and method for multiple inverters operating in parallel, wherein the multiple inverters at least comprises a first inverter and a second inverter connected in parallel. The islanding detection system comprises a current detection circuit arranged on a grid side or an AC side of the second inverter; and a controller connected to the current detection circuit and the first inverter. The controller determines whether to perform distributed islanding detection or centralized islanding detection on the first inverter and the second inverter according to a grid voltage signal and a current detection signal of the current detection circuit. By recognizing the islanding detection mode of the second inverter, matching it with typical islanding detection modes preset in a library, and determining to perform a distributed or centralized islanding detection according to matching results, the application improves the success ratio of islanding detection.