The　radiosity　is　one　of　the　popular　algorithms　for　radiation　simulation　within　a　virtual　canopy.　However,　owing　to　the　complexity　of　plant　architecture,　enormous　computation　on　computing　the　form　factors　has　become　a　serious　burden.　Thus,　a　new　optimized　strategy　of　radiosity　based　on　CUDA　and　3D　voxel　traversal　was　developed　to　improve　computation　efficiency.　Taking　simulation　of　radiation　transfer　within　a　virtual　Loquat　canopy　as　an　example,　our　proposal　is　based　on　uniform　partition　of　bounding　box　and　voxels　traversing　along　a　3D　line　to　identify　occlusion　between　the　light　source　and　tree　model　facets,　combining　GPU　to　compute　form　factor　in　parallel　using　CUDA.　Furthermore,　we　adopted　reduction　algorithm　and　shared　memory　to　optimize　the　radiation　flux　calculation.　Compared　with　serial　implementation　on　CPU,　the　results　are　good　in　terms　of　execution　times　with　speed-ups　about　150.　By　comparative　analysis　with　ray　tracing　and　traditional　radiosity　model　(progressive　refinement　radiosity　algorithm),　the　simulation　results　of　PAR　distribution　are　similar　and　consistent.　The　results　of　comparison　show　that　the　new　method　not　only　improve　computation　efficiency,　but　also　insure　the　accuracy.　©　2018,　Research　and　Development　Office　of　Wuhan　University.　All　right　reserved.