When solving complex multi-granularity decision-making problems， traditional three-way decision models based on functions or relationships tend to ignore the multi-granularity characteristics of information in reality and the limitations of the cognitive ability of decision makers. Based on it， this paper proposes a multi-granularity intuitionistic fuzzy three-way decision model based on regret theory. Firstly， to deal with complex calculation problems of intuitionistic fuzzy numbers， the θ operator is integrated with intuitionistic fuzzy rough sets， a multi-granularity upper and lower approximation operator for intuitionistic fuzzy rough sets is proposed， and the corresponding three-way decision rules are given. Secondly， to integrate the cognitive characteristics of the decision-maker into the decision-making process， a multi-granularity three-way sorting method under optimistic and pessimistic strategies is constructed based on the regret theory. Finally， the effectiveness of the proposed model is verified by a group decision example of the competency assessment of “Chinese+vocational” talents in international Chinese education， which provides a new method for uncertain decision-making problems that integrate decision-maker risk preferences in an intuitionistic fuzzy environment.