In　this　paper,　we　propose　a　new　positioning　and　automatic　detection　algorithm　of　ballast　track　fastener　missing,　which　is　based　on　different　shooting　direction.　The　crossover　method　based　on　Fast-Kirsch　edge　detection　arithmetic　and　HOUGH　straight　line　detection　is　presented　for　the　direction-based　positioning　algorithm.　It　has　very　strong　transplantability　without　the　effect　of　shadow,　inclination　of　track,　obstacles　and　in　relatively　accurate　location　areas　for　missing　fastener　scanning,　FAST-PCA　is　used　as　the　feature　extraction　method　of　identification　after　the　comparison　of　several　algorithms.