In　recent　years,　unmanned　autonomous　vehicle　navigation　technology　or　UAV　research　is　a　hot　topic　in　the　field　of　machine　vision,　and　obstacle　detection　is　the　basis　of　autonomous　navigation.　In　this　thesis,　the　author　analyzed　the　deficiency　of　stereoscopic　vision　and　classified　current　monocular　obstacle　detection　algorithms.　According　to　the　properties　of　algorithms,　this　paper　elaborated　the　function　of　algorithms　based　on　features,　focal　length　and　movements　respectively.　The　author　also　discussed　current　situation　and　prospects　for　various　types　of　algorithms,　including　feature　extraction　and　matching,　focusing　and　defocusing　model,　background　subtraction,　frame　difference　and　optical　flow.　Finally,　this　paper　summarized　advantages　and　disadvantages　of　different　autonomous　navigation　algorithm　and　discussed　the　prospect　of　the　monocular　obstacle　detection　technology.