To　reveal　the　load-transfer　mechanism　of　stiffened　deep　cement　mixing　(SDCM)　piles,　the　three-dimensional　numerical　analysis　of　a　pilot　pile　was　first　conducted　using　the　finite　element　software　Diana,　which　can　simulate　the　Mohr-Coulomb　friction　interface.　Comparisons　show　that　the　computed　load-settlement　curve　and　distribution　law　of　the　skin　frictions　agreed　well　with　the　measurements.　Then,　the　numerical　method　was　employed　to　model　the　group　pile　foundations　with　four　SDCM　piles.　It　shows　that　the　bearing　capacity　increased　with　increasing　pile　spacing　and　core　lengths.　And　most　loading　was　shared　by　the　stiffened　cores.　It　indicates　that　negative　skin　frictions　may　arise　at　the　bottom　of　a　reinforced　concrete　pile　cap　or　the　end　of　a　stiffened　core.　And　there　is　a　hysteresis　effect　for　the　peak　frictions　on　the　two　interfaces　to　mobilize.　Meanwhile,　plastic　shear　zones　in　soil　and　DCM　pile　may　sequentially　arise　with　increasing　load.