采用分子动力学模拟方法，研究了βＢａＢ２Ｏ４晶体生长母液ＢａＢ２Ｏ４Ｎａ２Ｏ二元系熔体的结构，Ｎａ２Ｏ摩尔浓度分别为１２５％，２０％，２５％，３０％．模拟给出的不同组分比下的ＢＯ径向分布函数表明，随着Ｎａ２Ｏ浓度的增加，第一峰峰值更高，峰形更尖锐．在模拟产生的一系列瞬态构型基础上，采用键序参数方法，结合环链统计，研究了母液溶体的局部结构．结果表明，助熔剂Ｎａ２Ｏ的加入，提高了熔液中ＢＯ３平面三角形基团的含量，且使游离ＢＯ３，Ｂ２Ｏ５，Ｂ３Ｏ７等结构单元增多，同时大大削弱了体系网联程度，有利于平面Ｂ３Ｏ６环的形成，也有利于晶体生长．统计分析还表明，Ｂ原子在游离ＢＯ３中的百分比与母液熔体挥发度实验值、Ｂ原子在长链中所占百分比与母液熔体粘度实验值均有很好的对应关系 The structure of BaB2O4Na2O binary system melt was studied by molecular dynamics simulation. The Na2O molar concentrations were 125%, 20%, 25% and 30% respectively. The BO radial distribution function under different composition ratios shows that with the increase of Na2O concentration, the peak value of the first peak is higher and the peak shape is sharper. Based on a series of transient configurations generated by the simulation, the local structure of the mother liquor solution was studied by the bond order parameter method and the statistics of the chain. The results show that the flux of Na2O increases the content of BO3 planar triangular groups in the melt and increases the number of structural units such as free BO3, B2O5 and B3O7. Meanwhile, the degree of network interconnection is greatly weakened, which is in favor of the plane B3O6 ring Formation, but also conducive to crystal growth. Statistical analysis also showed that the percentage of B atom in free BO3 is proportional to the experimental value of the mother liquor melt volatility and the percentage of B atoms in the long chain to the experimental value of the mother liquor melt viscosity