摘要:Abstract Rough set theory has a very good effect in information processing and knowledge discovery. In an information table, the current scholars regard all objects as a universe, and then establish various rough set models. However, in the analysis of many data problems, it is more reasonable to select parts of objects which are useful to us or can meet the actual needs as a universe. Therefore, in order to make up for the deficiency of traditional models, a new model is introduced from the perspective of variable universe. Then, some interesting properties of this model, such as approximation sets, reduct of attributes and maximum part of universe, are discussed. Through the study of this paper, it can be seen that the model developed in our paper is not only more accurate but also more effective in describing uncertain knowledge.