The main considerations in the deep-blue organic electroluminescence materials entail optimizing the utilization of non-radiative triplet excitons, alongside attaining exceptional stability and minimizing efficiency roll-off, thereby enhancing their overall performance. In this work, we develop a new hybridized local and charge-transfer (HLCT) fluorophore, namely BOE, by incorporating a rigid and planar oxygen-bridged triphenylborane skeleton with anthracene and naphthalene units. The rigid and near-orthogonal molecular geometry endows it with excellent morphological stability and a rapid radiative transition rate, while maintaining deep-blue emission. Consequently, the non-doped device, exhibiting color coordinates of (0.154, 0.076), demonstrates an external quantum efficiency (EQE) of 5.14%, as well as a small roll-off of 8.4% at 1000 cd m-2. By using it as a host for 1-4-di-[4-(N,N-diphenyl)amino]styryl-benzene (DSA-Ph), the device shows a maximum EQE of 5.31% at a ultra-high luminance of 28651 cd m-2. This work offers profound guidance for the development of high-performance, novel HLCT materials that exhibit both high stability and low efficiency roll-off.