A　hydraulic　cementitious　material　was　prepared　by　using　rice　husk　ash,　CFB　desulfurization　ash　and　steel　slag,　which　can　replace　cement　for　soil　solidification.　In　order　to　improve　the　activity　and　other　properties　of　this　cementitious　material,　the　performance　change　and　mechanism　of　the　clinkerless　cementitious　material　after　mechanical　grinding　were　studied.　The　results　show　that　with　the　increase　of　grinding　time,　the　particle　size　distribution　curve　of　the　cementitious　materials　changes　from　multi-peak　distribution　to　single-peak　distribution,　the　water　consumption　of　standard　consistency　decreases　and　the　setting　time　shortens.　The　end　time　of　the　hydration　induction　period　and　the　appearance　time　of　the　second　exothermic　peak　were　significantly　advanced,　and　the　cumulative　heat　release　increased.　The　early　compressive　strength　and　autogenous　shrinkage　of　mortar　specimens　increased　significantly.　The　initial　flow　expansion　degree　of　the　fluidized　solidified　soil　prepared　by　the　cementitious　materials　increases　with　the　increase　of　grinding　time,　and　the　time-dependent　loss　accelerates.　Mechanical　grinding　had　no　significant　effect　on　the　early　strength　of　the　solidified　soil,　while　the　later　strength　increases　first　and　then　decreases.　Using　this　cementitious　material　without　clinker　to　prepare　fluidized　solidified　soil　can　meet　the　strength　requirements　of　general　backfill　projects.　©　2024　Chongqing　University.　All　rights　reserved.