<p>Picture fuzzy sets (PFSs) are an advanced extension of fuzzy sets that effectively address uncertainty and fuzzy information in the Multi-attribute Group Decision-Making (MAGDM) process. In this paper, we propose an extended TODIM model based on CRiteria Importance Through Inter criteria Correlation (CRITIC) method and Regret theory (RT) in picture fuzzy environment. First, an improved CRITIC method with PFSs is developed to deal with the decision problems of unknown criteria weights. Then, a modified TODIM method based on picture fuzzy distance is introduced to calculate the overall dominance degrees of alternatives. After that, considering that decision-makers have limited rationality, with the psychology of loss aversion and regret avoidance in the evaluation process, the regret theory is used to select the best scheme by calculating the perceived utility values. Finally, the proposed PF–CRITIC–TODIM–RT method is applied to green suppliers selection, and comparative analyses are also conducted to demonstrate its superiority in capturing nuanced differences, handling unknown criterion weights, and incorporating psychological behavior. Additionally, Spearman’s correlation tests validate the method’s reliability and stability, showing it outperforms other MADM methods in terms of consistency and adaptability.</p>