以荧光强度为指标，采用L9(34)正交实验优化纳米荧光粉YPO4:2%Sm3+的水热工艺条件(反应温度、反应时间、溶液的阴/阳离子比和pH值)。用X射线衍射仪(XRD)、扫描电镜及能谱(SEM and EDS)、荧光分光光度计(FL)、红外光谱仪(FT-IR)和紫外光谱仪(UV)等仪器对样品的组成、结构、形貌及其发光性能进行了表征和分析。结果表明，影响纳米荧光粉YPO4:2%Sm3+水热工艺条件的主次因素为反应温度>pH值>反应时间>阴/阳离子比。最佳的水热工艺条件为反应温度为200℃、pH=3、反应时间为12 h、阴/阳离子比3:1。最佳纳米荧光粉的结构为单一的四方晶体结构，形貌为纳米球，荧光强度最大，荧光寿命为0.1719 ms，禁带宽度为5.14 eV，色坐标为X=0.5563, Y=0.4339。

In order to study the optimal hydrothermal process conditions of nano-phosphor YPO4:2%Sm3+, using the fluorescence intensity as an indicator, the hydrothermal process conditions (reaction temperature, reaction time, the ratio of anion to cation in the solution and pH value) of the nano-phosphor YPO4:2%Sm3+ were optimized by L9(34) orthogonal experiment. Then, the composition, structure, morphology and luminescent property of the sample were characterized and analyzed by X-ray diffractometry (XRD), scanning electron microscopy (SEM and EDS), infrared spectrometer (FT-IR), ultraviolet spectrometer (UV) and fluorescence spectrophotometer (FL). The experimental results showed that the primary and secondary factors affecting the hydrothermal process conditions of nano-phosphor YPO4:2%Sm3+ were reaction temperature>pH value>reaction time>the ratio of anion to cation. The optimal hydrothermal process conditions of nano-phosphor YPO4:2%Sm3+ were reaction temperature of 200℃, pH=3, reaction time of 12 h, the ratio of anion to cation of 3:1. The optimum nano-phosphors was a single tetragonal crystal with the morphology of nanospheres, the maximum fluorescence intensity, and fluorescence life time of 0.1719 ms, band gap of 5.14 eV, color coordinate of X=0.5563, Y=0.4339.