Abstract: As treat each target equally,the traditional grey situation decision making method can’t reflect the preference of the decision maker and the actual problem: A new method for weight solution in situation decision making is proposed.First,the deviation between a certain affair and the rest affairs is calculated by a single target.Similarly,the deviation matrix is formed by total targets.Secondly,the weight of each target is computed by means of entropy.The entropy weight can reflect the difference of each situation better.This method improves the theory of grey situation decision making and the example also shows its feasibility.