The　work　aims　to　obtain　the　relationship　of　solid-liquid　interface　energy　changing　over　time　during　the　reaction　wetting　process　and　master　the　core　problem　of　reaction　wetting　kinetics.　Theory　derivation:　during　reaction　wetting　process,　three-phase　energy　was　in　dynamic　equilibrium　at　reaction　interface.　Based　on　this,　new　phase　coverage　rate　at　the　reaction　interface　and　the　fraction　of　interface　active　element　occupancy　concentration　were　taken　as　two　variables　so　that　Young＇s　equation　and　the　boundary　conditions　could　be　used　for　mathematical　derivation.　Dezelluss　cosθ-t　relationship　dynamic　equation　was　also　used　for　further　theoretical　derivation.　Experimental　verification:　NiSi　alloys　were　refined　by　vacuum　melting　furnace,　and　wetting　experiments　on　graphite　substrate　were　carried　out　in　a　high　temperature　vacuum　humidifier　by　modified　seat　drop　method.　Change　of　contact　angle　during　the　reaction　wetting　process　was　recorded　by　a　high　resolution　CCD　camera　to　get　contact　angle　data.　The　kinetic　equation　was　verified　by　the　data　and　formula.　Through　theoretical　derivation,　kinetic　equation　of　the　relationship　between　solid-liquid　interface　energy　and　time　was　derived.　This　equation　was　the　same　as　the　equation　with　instantaneous　difference　of　solid-liquid　interface　energy　as　driving　force　during　reaction　process,　and　also　identical　to　the　equation　derived　by　the　Dezelluss　cosθ-t　relationship.　In　the　kinetic　equation,　the　solid-liquid　interface　energy　was　exponentially　reduced　over　time.　Results　of　wetting　experiment　by　Ni-Si/C　system　showed　that　solid-liquid　interface　energy　decreased　exponentially　with　reaction　time　during　the　interface　reaction　control　stage,　which　was　consistent　with　solid-liquid　interface　energy　changing　with　reaction　time　in　the　theoretically　derived　kinetic　equation.　Moreover,　the　activation　energy　of　interfacial　reaction　of　Ni-45wt%Si/C　system　was　calculated　to　be　239　kJ/mol　in　combination　with　the　kinetic　equation　and　Arrhenius　equation,　which　was　close　to　the　value　reported　in　literature.　The　reaction　kinetics　equation　is　reliable　in　reactive　wetting　process.　The　relationship　between　solid-liquid　interface　energy　and　time　is　exponentially　reduced,　which　can　provide　a　theoretical　reference　for　surface　modification　and　wettability　in　coatings.　©　2019,　Chongqing　Wujiu　Periodicals　Press.　All　rights　reserved.