In　this　work,　a　direct　numerical　simulation　method,　for　pore　scale　particle-water-oil　transport　in　porous　media　is　proposed　in　hybrid　Eulerian-Lagrangian　framework.　In　this　method,　Navier-Stokes　equation　in　Eulerian　framework　is　coupled　with　discrete　element　method　(DEM)　in　Lagrangian　framework　through　direct　numerical　evaluation　of　fluid-particle　interaction　using　fictitious　domain　method　(FDM).　In　Eulerian　framework,　volume　of　fluid　(VOF)　method　is　employed　to　capture　immiscible　two-phase　interface;　Ghost　fluid　method　and　balanced-force　scheme　are　used　to　treat　the　surface　tension　to　lower　interface　spurious　currents.　In　Lagrangian　framework,　RIGID　algorithm　is　employed　to　detect　the　contact　states　between　spherical　particles　with　arbitrarily　topological　pore　walls,　making　the　method　adapt　to　arbitrary　pore　space;　Injection　of　particles　with　arbitrary　size　distribution　at　a　specific　mass　flow　rate　makes　the　method　adapt　to　open　system.　After　validating　the　new　method　using　two　benchmark　test　cases,　a　numerical　simulation　of　particle　flooding　process　in　a　real　rock　is　performed.　Numerical　results　show　that　in　the　particle　flooding　process,　three　different　stages,　i.e.　drainage　period,　analogy　water　flooding　period　and　effective　period　of　particle　flooding,　are　involved.　Distinct　macroscopic　flow　characteristics　are　observed　in　different　periods.　Particle　size　is　an　important　factor　influencing　the　pore　scale　behaviors　(such　as,　particle　space　translation　and　diffusion,　remaining　oil　distribution,　degree　of　fluid　diversion)　and　macroscopic　flow　phenomena　(such　as,　average　oil　fraction,　average　water　or　oil　migration　velocity　in　mainstream　direction　and　transverse　direction,　sweeping　efficiency).