To　improve　the　mechanical　properties　and　deformation　stability　of　stabilized　sludge,　a　new　type　of　eco-friendly　curing　agent　with　cement,　slag,　fly-ash　and　gypsum　(CSFG)　as　materials　and　fiber　reinforcement　(FR)　is　developed.　Through　the　unconfined　compression　test　and　permeability　test,　the　effects　of　different　CSFG　contents　(10%,　20%,　30%),　different　fiber　lengths　(0,　3,　6,　12　mm),　and　different　fiber　contents　(0%,　0.2%,　0.4%,　0.8%)　on　the　mechanical　properties　and　permeability　of　the　samples　are　compared　and　further　analyzed.　In　addition,　the　micro　mechanism　of　the　CSFG-FR　synergistic　effect　is　analyzed　and　explored　by　X-ray　diffraction　(XRD),　scanning　electron　microscope　(SEM)　and　nuclear　magnetic　resonance　(NMR).　The　main　conclusions　are　as　follows:　(1)　The　mechanical　properties　of　CSFG-FR　stabilized　samples　are　significantly　improved,　and　the　failure　mode　has　changed　from　brittle　failure　to　ductile　failure.　Moreover,　the　deformation　properties　are　improved,　while　the　improvement　effect　of　permeability　is　inapparent.　(2)　The　fiber　has　a　critical　content　(0.4%),　which　plays　a　positive　role　on　properties　improvement　when　the　fiber　is　less　than　the　critical　content　and　have　a　side　effect　by　contrary　when　it　exceeds　the　critical　content.　(3)　Through　forming　a　three-dimensional　fiber　network,　the　fiber　can　promote　the　distribution　of　hydrate　and　guide　the　hydrate　to　adhere　to　its　surface,　thus　exerting　the　synergistic　effect　of　CSFG-FR.　The　optimal　fiber　content　is　0.4%　and　the　optimal　fiber　length　is　12　mm.　©　2022,　Science　Press.　All　right　reserved.