For　solving　the　neutron　transport　equation　in　complex　geometry,　the　discrete　direction　probability　method　(DDPM)　is　developed.　In　the　DDPM,　the　calculation　system　is　divided　into　subsystems　which　can　be　subdivided　into　fine　meshes.　The　ray　tracing　is　done　for　each　type　of　subsystem.　Within　a　subsystem,　fine　meshes　are　coupled　by　the　discrete　direction　collision　probability,　while　subsystems　are　coupled　by　the　discrete　direction　transmission　probability.　The　numerical　results　demonstrate　the　high　efficiency　and　accuracy　of　this　method.