This　paper　presents　a　zero-optical-distance　mini-LED　backlight　with　cone-shaped　light　coupling　microstructures　to　achieve　an　ultra-thin　backlight　architecture　(similar　to　0.1　mm　thickness)　by　combining　the　characteristics　of　direct-lit　and　edge-lit　backlights.　There　is　no　gap　between　the　light　guide　plate　(LGP)　and　the　reflector,　as　well　as　between　the　LGP　and　the　mini-LED　embedded　in　the　reflector.　The　illuminance　uniformity　and　light　extraction　efficiency　(LEE)　of　the　whole　structure　reach　91.47%　and　77.09%,　respectively.　Nine　sub-modules　are　spliced　together　to　realize　2D　local　dimming　with　0.29%　crosstalk.　The　structure　shows　high　optical　performance　while　reducing　the　thickness　of　the　backlight　module,　which　is　of　great　significance　for　the　development　of　mini-LED　backlights.