Improving　micro-electro-mechanical　inertial　navigation　system　based　indoor　pedestrian　localization　is　a　hot　and　hard　topic　these　days.It　is　because　random　errors　of　MEMS　gyroscopes　and　accelerators　are　very　complicated,and　very　difficult　to　model　using　norm　techniques.In　this　paper,a　map　matching　method　based　on　conditional　random　fields　and　indoor　3D　map　is　proposed.The　algorithm　is　designed　by　establishing　the　mathematical　relationship　between　the　inertial　position　and　the　interior　points　of　indoor　map,and　the　optimal　trajectory　algorithm　is　used　to　get　the　estimated　locations.The　position　errors　of　inertial　navigation　are　corrected　according　to　the　matching　points　solved　by　the　algorithm.　©　2021,　Chinese　Institute　of　Electronics.　All　right　reserved.