The　water　cooling　method　for　traditional　power　modules　will　increase　the　volume　of　the　cooling　system　additionally.　And　the　thermal　resistance　of　the　internal　ceramic　conductive　substrate　becomes　a　bottleneck　to　further　improve　the　cooling　capability　of　the　module.　In　this　paper,　the　heat　dissipation　method　using　immersion　oil　cooling　(IOC)　is　proposed,　which　directly　flows　the　insulating　oil　through　the　cavity　of　the　power　module,　and　directly　dissipates　heat　from　the　power　dies　and　the　ceramic　conductive　substrate,　thereby　reducing　the　additional　heat　conduction　path.　To　further　optimize　the　heat　dissipation　capacity　of　IOC,　this　paper　mainly　studies　the　open　hole　specifications　of　the　oil　inlet　and　outlet,　internal　integrated　heat　sink,　and　advanced　packaging.　The　results　show　that　IOC　can　well　assume　the　function　of　insulation　and　heat　exchange　with　the　outside.　©　2022　IEEE.