The invention provides a rapid composting method for ecological bank slope soil. The rapid composting method comprises the steps that (1), kitchen wastes without grease and salt are mixed with crop residual products, after high-temperature dehydration and sterilization, the mixture and waste mushroom fungus sticks which are sterilized at high temperature are mixed and smashed into particles; (2),in a container, the mixed particles and a few of biochar particles are laid layer by layer; (3), the container is subjected to semi-ventilation fermentation for one day at the temperature of 60-80 DEGC and cooled to room temperature; (4), after fermentation is completed, materials in the container are significantly stirred and mixed to obtain compost ecological soil; (5), the compost ecological soil obtained after fermentation is further smashed into a granular structure of 1-2 micrometers. The ecological bank slope soil processed by using the method can provide microorganisms and nutrients for a bank slope environment, the soil breathability can be enhanced, the bank slope structure is stabilized, a slope runoff purifies soil water, and contamination, caused by eutrophication, to water and soil is reduced.