Five　modification　methods　are　adopted　for　wheat　straw　fibers　(WSFs).　The　effects　of　modification　methods　on　the　water　absorbency　of　wheat　straw　fiber/wheat　straw　fiber　cement-based　composite　(WSFCC)　and　the　mechanical　properties　of　WSFCC　are　analyzed.　The　crystallinity,　chemical　structure,　and　micromorphology　of　WSFs　and　WSFCC　28-day　specimens　are　characterized　by　XRD,　FTIR,　and　SEM　methods.　The　results　show　that　the　water　absorption　of　WSFs　modified　with　sodium　silicate　solution,　pure　acrylic　acid　emulsion,　and　silicone　waterproof　emulsion　surface　spraying　is　10.67%,　5.18%,　and　1.05%　lower　than　that　of　unmodified　WSFs,　respectively.　Alkali　modification　is　the　ideal　method　for　improving　the　strength　of　WSFCC.　Establishing　a　fitting　formula　of　the　relationship　between　water　absorption　of　WSFs　and　strength　of　WSFCC　specimens　has　important　theoretical　and　practical　guiding　significance　for　development　and　application　of　WSFCC.