The invention discloses an intelligent anti-islanding device and an automatic islanding detecting and destroying method. The intelligent anti-islanding device is characterized by comprising an islanding detecting module, an islanding recognizing module, an islanding destroying module, an islanding alarm module and an islanding transmitting module, wherein the islanding detecting module is connected with the islanding recognizing module, the islanding recognizing module is connected with the islanding destroying module and the islanding alarm module, and the islanding transmitting module is connected with the islanding detecting module, the islanding recognizing module, the islanding destroying module and the islanding alarm module. The intelligent anti-islanding device has the advantages that by detecting and recognizing unintentional islanding automatically by the islanding detecting module, when islanding occurs in a power distribution line of a distributed photovoltaic power generation system, the intelligent anti-islanding device is capable of automatically detecting and recognizing unintentional islanding operation according to acquired line information, alarming automatically to inform a management system timely and controlling the anti-islanding device to switch automatically through a DSP (digital signal processor) controller to switch off the unintentional islanding so as to prevent potential safety hazard caused by manual operation.