Contour filling is based on the topology relationship between contours，which remains a difficult research question.In order to fill contours fast and conveniently，a new automatic filling algorithm between contours based on triangulation irregular net was proposed.From the relationship between unclosed counters generated by the irregular triangulation net and the custom border，the closed counters were built，and then the filling color between contours was determined through determining the relationship of the closed counters，so the contour filling chart was mapped.This algorithm is easy to implement and the computing speed can meet the business needs.