As　subgrade　with　saturated/unsaturated　soil　in　seasonal　frozen　region,　the　frost　heave　disease　is　more　concerned　recently.　In　order　to　further　understand　the　distribution　of　the　temperature　field,　moisture　field　and　stress　field,　and　the　development　of　frost　heave　deformation,　first　a　multi-physics　coupling　control　equation　was　established,　based　on　energy　conservation　law,　mass　conservation　law　and　Darcy＇s　law.　Then　based　on　VG　model　and　the　relationship　between　saturation　and　hydraulic　head,　a　numerical　model　which　is　combined　with　the　apparent　heat　capacity　method　was　established.　Finally　the　model　was　verified　by　compare　the　results　from　lab　test.　This　model　was　used　to　predict　the　development　of　the　frost　heave　deformation　and　evolution　law　of　each　parameter　for　seasonal　frozen　soil.　And　it　can　provide　a　theoretical　basis　for　anti-freezing　design　and　evaluation　of　frost　disease.　©　2016　Taylor　&　Francis　Group,　London.