A　fast　optimization　method　based　on　the　diffuser　dot　density　(DDD)　for　uniformity　of　the　backlight　module　(BLM)　is　proposed　in　the　paper.　First,　the　relationship　between　the　efficiency　of　the　light　emerging　and　the　DDD　is　analyzed,　and　then　a　simulation　model　that　is　employed　to　acquire　a　serial　of　simulating　data　is　constructed.　Second,　a　mathematic　method　to　profit　the　relationship　is　adopted,　and　a　polynomial　relationship　is　derived.　Finally,　an　algorithm　to　adjust　the　DDD　and　optimize　the　uniformity　of　the　BLM　based　on　the　DDD　is　constructed.　The　simulation　results　prove　that　only　by　three　times　optimization,　the　uniformity　of　the　BLM　can　reach　85.6%,　and　the　experimental　result　indicates　that　the　algorithm　proposed　in　the　paper　can　improve　the　uniformity　rapidly.　The　final　experimental　result　is　that　the　uniformity　of　the　third　optimization　reaches　77.4%,　which　satisfies　the　target　75%　in　the　phase　of　designing　the　BLM.　Compared　to　the　conventional　optimization　method,　the　method　can　speed　up　the　procedure　and　lower　the　expense　of　developing　the　BLM　in　fabricating　the　liquid-crystal　display.　(C)　2016　Optical　Society　of　America