Multiple-resonance thermally activated delayed fluorescence (MR-TADF) materials have advantages such as narrowband emission, small singlet-triplet energy level differences, and large molar extinction coefficients. These characteristics enable a combination of high efficiency and high color purity, granting these materials significant application potential in ultra-high-definition displays. Consequently, they have gained widespread attention. Since the first MR-TADF material was reported in 2016, this field has witnessed rapid advancements. However, blue MR-TADF materials with higher energy levels often suffer from poor carrier injection and transport capabilities, limiting their performance in terms of efficiency and color purity. MR-TADF materials with multi-boron structures, owing to their multiple electron-deficient boron atoms, enhance electronic delocalization and molecular orbital overlap and coupling. This suppresses non-radiative transitions and improves emission efficiency. Moreover, the increased molecular rigidity and multi-resonance effects reduce vibrational and rotational energy level distributions in the excited state, resulting in narrower full width at half maximum (FWHM) emissions. Consequently, these materials have emerged as a prominent choice for constructing deep blue organic emissive materials, driving significant progress in this field. In this paper, we comprehensively explore recent advances in blue MR-TADF materials with multi-boron structures, focusing on molecular design, photophysical properties, and optoelectronic performance in organic light-emitting diodes (OLEDs). By clarifying the relationship between molecular structure and performance, we aim to provide valuable guidance for future research. Finally, we present perspectives on the future development of blue boron-containing MR-TADF materials.