Abstract: In response to the frequent icing of 110kV transmission lines caused by the special micro weather in the high-altitude reservoir area on the dam, and the inability of conventional inspection standards and power outage melting methods to adapt to on-site working conditions, this study aims to reduce the mechanical damage, insulation flashover and other power grid faults induced by icing. A graded warning standard for icing is established, and a four-dimensional differentiated special inspection system is constructed, which includes meteorological pre positioning, ground fixed-point, unmanned aerial vehicle cruising, and online monitoring linkage. Four sets of optimization technologies are innovatively adopted, including SVG dynamic reactive power live melting, segmented controllable short-circuit melting, lightweight robot fixed-point de icing, and silicon-based coating pre protection. Actual test data shows that the thickness of ice coating on the wire after spraying protective coating has decreased by 61%. Reactive power of 11.3Mvar and 19.7Mvar can be used to complete live ice melting in the 10-40mm ice coating range. The hidden danger of repeated ice coating on the original overload limit of 78.6% has been effectively controlled. Research has shown that this inspection and composite de icing scheme can eliminate the shortcomings of power outage operations and comprehensively suppress the risk of icing operation on the dam line from the perspectives of monitoring, prevention, and pre protection.