The invention discloses a self-triggering power transmission line insulator pollution flashover early-warning device, which comprises a leakage current sensor and a device main body, wherein the leakage current sensor is connected with the device main body through a buckle; the device main body comprises a low-pass filter, a rectifying circuit, a stepper, a comparator, a single chip microcomputer, a GPRS module, a battery, a humidity sensor, a wireless communication module, a GPRS antenna and a wireless communication antenna; the leakage current sensor, the low-pass filter, the rectifying circuit, the stepper, the comparator and the single chip microcomputer are connected in sequence; the single chip microcomputer is respectively connected with the GPRS module, the battery, the humidity sensor and the wireless communication module; the GPRS module communicates with mobile equipment through the GPRS antenna; and the wireless communication module communicates with handheld patrol inspection equipment through the wireless communication antenna. The self-triggering power transmission line insulator pollution flashover early-warning device achieves the effects of detecting pollution condition of the insulator regularly and sending out pollution flashover early-warning when pollution accumulation is severe.