The invention discloses a method and a device for power information detection and interconnection self-decision analysis, belonging to the field of power system data acquisition. The device for power information detection and interconnection self-decision analysis comprises a master station, a controller and a load control terminal. The controllers are communicated through GPRS; the controller comprises a processor, a programmable logic device, an A/D sampling circuit, an analogue voltage current collection circuit, an optical fiber connecting interface circuit and a GPRS module, wherein the analogue voltage current collection circuit comprises a voltage measuring circuit, an alternating current voltage signal modulating circuit, a current measuring circuit and an alternating-current current signal modulating signal; and the optical fiber connecting interface circuit comprises a pair of photoelectricity receiver/sender. The device is placed into a power network, the controllers are communicated with each other, thereby the invention is beneficial to monitoring power data among cells; and because of a fault self-diagnosis function, the power department judges fault points and fault reasons through the power data, thereby the invention is beneficial to monitoring a power system.