The invention relates to a power grid wind damage early warning system based on micro-landform wind field distribution and typhoon superimposed effect, belonging to the field of prevention, reduction and control of natural disaster for a power grid. The power grid wind damage early warning system comprises a weather data acquisition sub-system, a wind damage and wind speed forecasting computer sub-system, a power grid early warning information processing computer sub-system, a power grid wind damage estimation processing computer sub-system and an information issuing sub-system, and each above sub-system is orderly in signal electrical connections. The power grid wind damage early warning system is capable of acquiring timed weather data of meteorological stations in a region covered by the power grid, performing standard pretreatment, then, establishing a gale statistical diagnosis model and a numerical model by means of theory modeling and numerical simulation, analyzing influence degree of the gale on main lines, iron towers and transformer substations, and issuing a related gale early warning information report based on related rules for gale early warning grades, wherein the related rules are specified by the Meteorological Office. And the power grid wind damage early warning system has the advantages of high precision, excellent accuracy, quick real-time response speed and the like, and can provide decision support for gale damage prevention and power grid planning.