The methods and processes of macro site selection and wind turbine automatic arrangement of mountain wind farm are studied. The general methods and processes of macro site selection of wind farm are summarized and analyzed. According to the characteristics of mountain wind farm, a method of mountain wind farm site selection and automatic arrangement based on ridgeline extraction is proposed. Based on wind energy resource data and terrain data, this method combines geographic information technology to preliminarily select the range of mountain wind farm. Using spatial analysis tools to carry out landuse analysis, the restrictive factors that can not be used for site construction within the range was eliminated, so as to screen out the suitable mountain development land. Watershed feature is used to extract ridgeline, and equipment selection, layout strategy and wind energy density map are considered to realize automatic arrangement of wind turbines in mountain wind farm.