Background　Recognition　of　markers　in　the　augmented　reality　system　can　reduce　the　additional　cost　of　a　guide　plate　required　for　the　removal　of　benign　tumours　in　oral　and　maxillofacial　surgery,　but　the　use　of　markers　often　has　complex　problems.　Method　In　order　to　avoid　the　complex　problem　of　using　markers,　an　augmented　reality　system　based　on　a　marker-free　registration　method　was　proposed　to　track　the　contour　of　the　mandible　edge.　Use　the　computer　to　perform　preoperative　planning　on　the　jaw　model,　select　and　mark　the　path　of　maxillofacial　lesion　resection.　Results　This　method　has　an　error　of　the　surface　matching　was　0.6453　+/-　0.2826　$0.6453\pm　0.2826$　mm,　and　an　error　of　the　surgical　resection　was　0.4858　+/-　0.3712　$0.4858\pm　0.3712$　mm.　Conclusions　We　demonstrate　that　the　system　can　accurately　enhance　the　display　of　the　surgical　path　and　provide　guidance　for　the　tradition　of　maxillofacial　surgery.