Scattering　particles　in　nature　often　have　complex　structures　and　shapes,　which　poses　a　great　challenge　to　study　the　optical　transport　in　scattering　media.　This　paper　proposes　what　we　believe　to　be　a　novel　Monte　Carlo　simulation　approach　based　on　the　finite-difference　time-domain　(FDTD),　capable　of　modeling　the　transmission　characteristics　of　light　fields,　including　intensity　and　polarization,　in　complex　scattering　media　composed　of　asymmetric,　polydisperse　particles.　This　method　overcomes　the　limitations　of　conventional　Monte　Carlo　methods　that　rely　on　Mie　scattering　with　spherical　particles,　which　are　insufficient　for　accurately　simulating　the　depolarization　characteristics　of　light　fields　in　anisotropic　scattering　media　composed　of　complex　particles.　In　order　to　verify　the　feasibility　of　this　method,　the　oil　smoke　scattering　model　was　established　for　the　oil　smoke　scattering　medium.　The　approximate　consistency　between　the　simulation　results　of　the　depolarization　characteristics　and　the　experimental　measurement　results　verified　the　effectiveness　of　this　method　in　simulating　the　light　field　intensity　and　depolarization　characteristics　in　scattering　media　composed　of　complex　particles.　©　2025　Optica　Publishing　Group　under　the　terms　of　the　Optica　Open　Access　Publishing　Agreement.