Today HDR (High Dynamic Range) Displays are increasingly developed. The HDR Display with mini‐led backlight and liquid‐crystal panel plays an important role, it has a lot of advantages like high light (more than 1000nits), high contrast ratio (more than 100000:1), bright color and good permeability and so on. But it also has some display defects like halo [3] phenomenon in a dark scene. In this paper, first, we discuss some common picture quality issues caused by the normal local dimming algorithm [2] and then present a novel algorithm base on BOE COG (chip on glass) mini‐led backlight HDR display. The BOE COG technology is a global unique glass substrate backlight solution, and has some features to help the algorithm improve its performance. And for the local dimming display issues, the algorithm itself has room for optimizing visual effects. Finally, around the key point of local dimming algorithm, we show several advantages of BOE glass substrate backlight solution, its distinctive features can help the algorithm improve picture quality.