Boric acid is an important chemical raw material, and the development of its lamellarization technology is crucial for enhancing its performance and broadening its application fields. In this study, based on the boric acid solution system purified by resin (LSI⁃020/010), the innovative introduction of sodium sulfate (Na2SO4) and magnesium sulfate (MgSO4) successfully induced the directional growth of boric acid crystals into a lamellar structure. The morphology characteristics of boric acid after additive incorporation was characterized using SEM. The effects of the introduction of MgSO4/Na2SO4 addition under weakly acidic conditions on the solubility of boric acid solution and the growth of crystal faces were analyzed by combining the COSMO⁃RS model and XRD. The interaction between MgSO4/Na2SO4 and boric acid crystals, as well as its impact on the B-O bond energy, was investigated using in⁃situ Raman spectroscopy. The results showed that boric acid exhibits a typical lamellar morphology after additive incorporation. The introduction of MgSO4/Na2SO4 under weakly acidic conditions significantly reduced the solubility of boric acid, promoting preferential crystal growth along the (002) and (004) planes. Moreover, the weak interaction between MgSO4/Na2SO4 and boric acid crystals reduces the B-O bond energy, which drove the growth of boric acid crystals towards lamellarisation. This study not only establishes a new boric acid lamellarization technology, but also elucidates the crystal growth mechanism at the molecular level, providing theoretical support for functionalized crystal engineering.