Ohmic　contact　is　an　important　expression　of　the　energy　band　change　after　metal-semiconductor　contact.　This　paper　summarizes　the　prerequisites　and　methods　for　achieving　ohmic　contact　in　the　experimental　process.　This　paper　sums　up　in　detail　the　several　important　factors　affecting　the　formation　of　ohmic　contact　during　the　experimental　process,　including　annealing　temperature　and　time,　epitaxial　method,　type　of　semiconductor　contact　layer　and　doping　concentration,　type　and　thickness　of　the　metal　contact　layer,　and　size　of　the　metal/semiconductor　contact　area,　etc.　We　propose　a　simple　and　effective　method　to　find　the　appropriate　annealing　temperature　and　time　by　determining　the　under-Annealing　and　over　annealing　states　of　ohmic　contact　during　the　annealing　process　through　a　Ring　Transmission　Line　Model.　Through　extensive　experimental　verification,　the　theoretical　reasoning　matches　well　with　the　experimental　results.　This　has　a　tremendous　role　in　Improving　experimental　efficiency.　©　COPYRIGHT　SPIE.　Downloading　of　the　abstract　is　permitted　for　personal　use　only.