The invention discloses an overhead wire icing on-line monitoring device based on machine vision, which is composed of hardware and software, wherein the hardware is divided into a lower computer and an upper computer; the lower computer hardware comprises a controlling and processing unit based on DSP, an image acquisition unit, a data acquisition unit, a data storage unit, a GPRS wireless communication unit and a solar energy photovoltaic light source unit; the upper computer hardware is composed of a monitoring center server unit and a GPRS wireless communication unit; and the upper computer hardware and the lower computer hardware realize wireless communication via a GPRS wireless network. The software is also divided into an upper computer and a lower computer, wherein, the lower computer software is in charge of driving the lower computer hardware to collect images and data, and the lower computer software calculates and judges icing thickness and type according to the collectedimage; then the GPRS wireless communication unit is driven to send compressed image and monitoring results to the upper computer; the upper computer software is in charge of driving upper computer hardware to finish GRPS wireless communication and realizes human-computer interaction interface and monitoring information management. The invention can monitor icing disasters on all sides.