To　explore　the　law　of　dynamic　processes　of　electromagnetic　mechanism　in　electrical　apparatus,　a　new　method　of　single　camera　three-dimensional　(3D)　measurement　is　proposed　in　this　paper.　By　means　of　a　high　speed　camera　and　optical　imaging　system,　3D　dynamic　characteristic　test　for　the　electromagnetic　mechanism　is　carried　out,　and　the　3D　dynamic　characteristic　curves　of　the　electromagnetic　mechanism　are　obtained　with　image　processing.　The　important　characteristic　values　of　3D　dynamic　characteristic　test　data　sample　functions,　such　as　the　best　estimated　value　and　the　measurement　uncertainty　are　analyzed.　The　relationship　between　the　uncertainty　and　the　number　of　tests　is　studied,　and　the　sample　size　is　determined　according　to　the　varying　trend　of　the　uncertainty.　Using　mathematical　statistics　method,　many　groups　of　3D　dynamic　characteristic　test　data　are　processed,　and　the　3D　dynamic　characteristics　of　the　electromagnetic　mechanism　are　analyzed.　The　study　results　show　that　by　means　of　3D　dynamic　characteristic　measurement　and　data　processing　methods,　the　3D　motion　process　and　the　motion　dispersivity　of　the　electromagnetic　mechanism　can　be　analyzed　effectively.　The　proposed　method　provides　the　basis　for　the　optimal　design　and　technics　improvement　of　electrical　apparatus　products.　©,　2014,　Science　Press.　All　right　reserved.