Abstract: Aiming at existing shortcomings including faultiness of rounding the obstacles and low-efficiency in the shortest routing based on binary tree,an improved method is proposed for building the shortest route automatically based on electronic navigation chart.Route is built automatically in complex cases with recursively search complex obstacle areas and optimizing collision avoidance rules,and is optimized by means of direction consistency check,boundary detection and dynamic envelope rectangle exclusion.The shortest route is obtained by strategy of recursive processing and dynamic estimation.Experimental results demonstrate that the proposed method has considerable advantages over the binary tree one in quality and efficiency of routing automatically.