The invention provides an electric power line crossing protection device comprising an insulation shielding sleeve, transmission parts and a power conversion part; the transmission parts and the power conversion part are arranged in the insulation shielding sleeve; each transmission part comprises three concave pulleys; one concave pulley is arranged on the top, the other two are arranged below, and the three pulleys are mutually connected by connecting springs, thus enabling crossed wires to penetrate and are fixed between the three concave pulleys; the power conversion part comprises a limit horizontal connecting rod and a driving rod used for pushing the limit horizontal connecting rod to slide; the central axles of the three concave pulleys are connected by the limit horizontal connecting rod; two ends of the limit horizontal connecting rod are respectively provided with a limit telescopic joint; the driving rod vertically moves downwards so as to push the limit horizontal connecting rod to move, thus enabling the limit telescopic joints to push the insulation shielding sleeve, and driving the electric power line crossing protection device to move forwards along the crossed wire. The electric power line crossing protection device is simple in structure, low in supplement cost, and not limited by places.