Aiming　at　the　problem　of　valve　port　erosion　caused　by　contaminated　particles,　a　threedimensional　prediction　model　of　valve　orifice　erosion　was　established　based　on　computational　fluid　dynamics　(CFD)　and　erosion　theory,　considering　the　influence　of　the　valve　port　eddy　current　on　the　oil　flow.　The　discrete　phase　model　(DPM)　of　fluent　is　used　to　obtain　the　orifice　erosion　location　and　erosion　rate,　and　the　causes　of　erosion　of　the　high-speed　on/off　valve　are　analyzed.　On　this　basis,　several　factors　influencing　valve　port　erosion　are　simulated　to　investigate　the　relationship　between　particle　collision　behavior　and　valve　port　erosion　morphology　under　different　factors,　and　the　change　rule　of　valve　port　erosion　under　different　factors　is　analyzed.　The　results　show　that　the　high-speed　on/off　valve　service　life　decreases　with　a　larger　cone　angle　of　the　spool,　a　larger　pressure　difference　at　the　valve　port,　a　larger　proportion　of　large　particle　contaminants　in　the　oil,　a　higher　oil　contamination　level,　and　a　larger　filter　aperture.　In　addition,　the　grey　relational　analysis　method　is　used　to　clarify　the　pressure　difference　at　the　valve　port,　the　particle　size,　and　the　filter　aperture　as　the　three　most　important　factors　affecting　the　erosion　of　the　valve　port　of　a　high-speed　on/off　valve.