本文对聚醚砜（ＰＥＳ）在不同溶剂和不同非溶剂中所构成三元体系的相分离进行研究。采用浊点滴定法测定了在常用溶剂和非溶剂中的浊点数据，溶剂对ＰＥＳ的溶解能力，依次为：甲酰胺＜二甲基亚砜＜Ｎ，Ｎ－二甲基甲酰胺＜Ｎ，Ｎ－二甲基乙酰胺＜Ｎ－甲基吡咯烷酮；以二甲基甲酰胺为溶剂，非溶剂的沉淀能力依次为：Ｈ２Ｏ＞丙三醇＞甲醇＞乙二醇＞乙醇＞丙二醇＞丙醇，线性浊点法能较好描述三元体系的浊点关系。这些研究为制膜浆液，尤其醇类作为添加剂制膜浆液的配制，提供了定量依据 In this paper, the phase separation of polyethersulfone (PES) in ternary systems composed of different solvents and different non-solvents was studied. The cloud point data of common solvents and non-solvents were measured by turbidimetric titration. Solubility of solvents on PES was evaluated as follows: formamide glycerol> methanol> ethylene glycol> ethanol> propylene glycol> Cloud point method can better describe the cloud point of the ternary system. These studies provide a quantitative basis for the formulation of film-forming slurries, especially alcohols as additive film-forming slurries