In　coastal　areas,　structures　such　as　cement-soil　dams　are　often　eroded　by　seawater,　so　it　is　significant　to　study　how　to　improve　the　impermeability　of　cement-soil.　Basalt　fiber　with　a　strong　tensile　property,　good　stability　and　a　high-performance　price　ratio　was　selected　as　the　additive　to　study　the　influence　of　the　basalt　fiber　content　on　the　permeability　of　soil-cement.　The　permeability　test　and　the　chloride　ion　permeability　test　were　used　to　evaluate　the　best　mixing　amount.　The　results　of　the　permeability　test　showed　that,　although　the　permeability　coefficient　of　soil-cement　decreased　with　the　increase　in　the　basalt　fiber　content,　the　decreased　rate　of　the　permeability　coefficient　showed　a　slowing　trend.　The　results　of　the　chloride　ion　permeability　test　indicated　that　the　chloride　ion-related　impermeability　of　soil-cement　was　enhanced　with　the　increase　in　the　basalt　content,　which　was　confirmed　by　the　consistent　findings　of　the　contrast　permeability　test.　The　comprehensive　analysis　shows　that　the　optimal　content　ratio　of　the　basalt　fiber　was　1.5%.　Furthermore,　a　SEM　analysis　established　that　the　addition　of　the　basalt　fiber　reduced　the　soil-cement　porosity,　improved　the　structural　compactness　and　formed　a　more　stable　whole.　This　study　could　serve　as　a　valuable　reference　for　soil-cement　used　in　projects　with　impermeability　requirements.　©　2023　by　the　authors.