In　this　paper,　preforms　with　three-dimensional　structures　and　different　thicknesses　were　constructed　by　3D　printing　technology,　and　WC　particle　reinforced　high-chromium　cast　iron　(HCCI)　composites　was　prepared　by　infiltration　casting　method.　The　microstructure　of　the　WC/Fe　matrix　composites　was　investigated　using　scanning　electron　microscopy　(SEM),　energy　spectroscopy　(EDS),　X-ray　diffraction　(XRD)　and　electron　backscattered　diffraction　(EBSD).　The　effects　of　different　preform　wall　thickness　on　the　hardness　and　three-body　abrasive　wear　properties　of　the　composites　were　tested.　The　results　showed　that　with　the　increase　in　the　wall　thickness　of　the　three-dimensional　preform　from　2.5　to　10　mm,　the　volume　of　the　composite　zone　formed　by　the　dissolution　diffusion　reaction　of　WC　and　HCCI　gradually　increased　from　31.8　to　41.2%.　The　microstructure　was　composed　of　composite　zone,　matrix　and　WC　particles　partially　dissolved.　The　hardness　of　the　composite　zone　increased　at　first　and　then　decreased,　while　the　wear　weight　loss　of　the　composite　showed　an　opposite　trend.　Compared　with　the　wall　thickness　of　2.5　mm,　the　minimum　wear　weight　loss　of　the　composite　was　0.2821　g　for　a　wall　thickness　of　7.5　mm,　and　the　wear　resistance　was　improved　by　12.8%.　The　hardness　and　wear　resistance　of　WC/Fe　matrix　composites　at　different　wall　thicknesses　were　mainly　related　to　the　diffusion　of　the　preform　and　the　formation　of　the　composite　zone.