The　effects　of　silicon　alloying　and　heat　treatment　on　the　microstructure　and　properties　of　Fe-35Cr-4C-xSi　(x　=　0.5,　1.2,　19,　2.6)　hypereutectic　high-chromium　cast　iron　(HHCCI)　were　explored　through　first-principles　calculations　and　phase　diagram　calculations　combined　with　XRD,　SEM,　TEM　and　other　methods.　With　the　increase　of　Si　content,　the　matrix　structure　of　HHCCI　transforms　from　martensite　to　ferrite.　The　phase　diagram　analysis　reveals　that　higher　silicon　content　results　in　elevated　austenite　transformation　initiation　temperatures,　reduced　austenite　phase　areas,　and　expanded　ferrite　phase　regions.　Additionally,　the　study　calculates　the　diffusion　activation　energy　of　C　atoms　within　silicon-bearing　and　silicon-free　HHCCI　matrices,　providing　valuable　insights　into　the　role　of　silicon　in　promoting　the　transformation　of　the　HHCCI　matrix　into　ferrite.　Notably,　silicon　facilitates　the　diffusion　of　C　atoms　into　the　silicon-bearing　HHCCI　matrix,　thereby　preventing　complete　austenitization.　After　ultra-high-temperature　heat　treatment,　the　matrix　structure　of　high-silicon　HHCCI　(1.9　wt.%　Si)　can　be　transformed　from　ferrite　to　martensite.　With　the　increase　of　Si　content,　the　corrosive　wear　resistance　of　HHCCI　increases　first　and　then　decreases.　The　1.9Si　HHCCI　after　ultra-high-temperature　heat　treatment　exhibits　the　best　corrosive　wear　resistance　in　both　acidic　and　alkaline　corrosive　wear　environments,　and　the　silicon-bearing　HHCCI　is　more　resistant　to　alkaline　corrosive　wear.　This　study　reveals　promising　applications　of　silicon-bearing　HHCCI　in　industries　such　as　hydraulics　and　coal　mining,　particularly　as　a　material　for　making　slurry　pumps.　Notably,　in　comparison　with　previous　work　by　our　research　group,　this　study　delves　deeper　into　the　mechanisms　underlying　the　structural　and　performance　changes　of　silicon-bearing　HHCCI　due　to　heat　treatment　and　silicon　content　variation.