Based on grey system theory and fuzzy theory, uncertain decision making problems and several relative articles were studied, then points out the advantage and shortage of them when dealing with grey fuzzy set were pointed out. In this paper, using optimization theory and the maximum entropy formulism, a method for multi-attribute group decision making based on the theory of grey fuzzy relation is established. Furthermore, two practical algorithms are given, in which attribute weights are known or unknown respectively. Finally, an example demonstrates the validity of this method.