In　order　to　gain　insight　into　the　influence　of　SiO2　support　particle　size　on　the　vacuum　residue　(VR)　slurry-phase　hydrocracking　performance　of　Fe-based　catalysts,　a　series　of　FeZn/SiO2　catalysts　with　varying　SiO2　particle　sizes　were　prepared.　Characterization　results　show　that　the　surface　area　and　pore　volume　of　the　FeZn/SiO2　catalysts　increase　with　the　reduction　of　SiO2　particle　sizes.　The　metals　Fe　and　Zn　species　on　FeZn/SiO2-S　catalyst　are　more　readily　reducible　via　H2-TPR　analysis.　Notably,　FeZn/SiO2-S　catalyst　presents　higher　metal　dispersion　and　a　greater　degree　of　sulfurization　compared　to　the　other　catalysts　by　XRD　and　XPS.　Hydrocracking　results　demonstrate　that　the　FeZn/SiO2-S　catalyst　achieves　the　lowest　coke　and　gas　yields　(11.9　wt%　and　0.4　wt%),　respectively,　and　the　highest　VR　conversion　among　these　catalysts.　The　superior　performance　of　the　FeZn/SiO2-S　catalyst　in　VR　slurry-phase　hydrocracking　is　ascribed　to　its　enhanced　hydrogenation　activity,　deriving　from　the　higher　dispersion　and　sulfurization　of　metals　species.　This　suppresses　the　aggregation　of　polycyclic　aromatic　hydrocarbons　in　VR　and　the　over-cracking　of　intermediate　products.　Additionally,　the　increased　mesopore　associated　with　smaller　SiO2　particles　facilitates　to　the　diffusion　of　large　VR　molecules,　further　promoting　the　hydrocracking　reaction.