Abstract: The present disclosure discloses a method for searching the shortest path of must-pass node, which includes the following processing steps: S1, constructing a Thiessen polygon; S2, when start node of must-pass nodes and end node of must-pass node are not the same must-pass node, performing processing of S3; S3, starting from the Thiessen polygon where the start node of must-pass nodes is located, querying the adjacent Thiessen polygons and merging them into the first merged polygon; S4, based on the first merged polygon, querying the unprocessed adjacent Thiessen polygons to merge the second merged polygon; S5, merging the isolated Thiessen polygon into a certain adjacent merged polygon with common edge; S6, deleting the edge lines of two vertices in Denaulay triangle that are not in the same merged polygon; S7.