A　new　construction　method　based　on　an　extended　graphite　sleeve　and　pre-forming　eutectic　is　described.　In　order　to　improve　the　temperature　gradient　along　the　HTFP　cell　and　avoid　thermal　stress　concentration　in　the　process　of　phase　transition,　the　crucible　is　designed　hybrid　structure,　namely,　placing　the　high　purity　graphite　foil　with　anisotropic　thermal　conductivity　between　the　graphite　sleeve　and　crucible.　Meanwhile　it　can　reduce　the　filling　times　effectively　which　can　decrease　the　introduced　external　contaminants　by　using　the　extended　graphite　sleeve.CCT-WG5　(Consultative　Committee　for　Thermometry,　Working　Group　5:　Radiation　Thermometry)　for　the　definition　of　thermodynamic　temperature　with　the　highest　level　of　Co-C　eutectic　HTFP　demands　the　repeatability　is　better　than　20　mK　and　the　difference　between　the　initial　temperature　and　the　end　temperature　of　melting　is　less　than　120　mK.　A　new　Co-C　eutectic　HTFP　was　constructed　based　on　the　new　filling　method,　and　the　preliminary　results　show　that　the　phase　transition　temperature　is　1324.054°C,　short-term　repeatability　is　better　than　9　mK,　and　the　difference　between　the　initial　temperature　and　the　end　temperature　of　melting　is　less　than　110　mK,　which　meet　the　CCT-WG5　requirements　for　the　HTFPs.