This　work　attempts　to　optimize　the　traditional　flow-reverse　reactor　by　establishing　a　three-dimensional　model　of　a　toluene　catalytic-combustion　reactor　through　computational　fluid　dynamics　(CFD).　Four　optimized　structures　are　designed:　(1)　20-mm　grille;　(2)　60-mm-long　lattice　plates;　(3)　20-mm-long　cross　plate　and　5-mm-thick　cross　plate;　and　(4)　20-mm-long　lattice　and　20-mm-long　and　5-mm-thick　cross　plate.　The　velocity　field,　pressure　drop,　temperature　field,　and　turbulent　energy　were　calculated.　The　results　show　that　the　area-weighted　evenness　index　of　the　four　structures　can　reach　(1)　0.910;　(2)　0.901;　(3)　0.909;　and　(4)　0.920.　The　results　also　show　that　the　reactor　with　a　20-mm　grid　and　5-mm　porous　plate　had　the　best　optimization　effect.　Based　on　the　reactor,　the　maximum　resistance　coefficient　of　the　optimized　flow　direction　conversion　reactor　was　0.030,　meeting　the　engineering　requirements.　The　results　from　the　temperature　fields　show　that　the　reactor　with　increased　flow　direction　greatly　improved　the　utilization　of　waste　heat.　It　was　also　confirmed　that　the　optimization　had　a　certain　guiding　significance　and　value　for　practical　application.