In order to meet the strict requirements for information in engineering management,the positive interval (0,1]in Shannon information entropy is extended to the real number interval[- 1,1].The information theory and the decision theory are combined effectively,and the deficiencies that the traditional Bayes decision-making methods only consider a single factor are made up for.The multi-factors engineering decision-making methods are proposed,and some critical problems are solved in the practical engineering management decision-making process. In order to meet the strict requirements for information in engineering management, the positive interval (0,1] in Shannon information entropy is extended to the real number interval [- 1,1]. The information theory and the decision theory are combined effectively, and the deficiencies that the traditional Bayes decision-making methods only consider a single factor are made up for the multi-factors engineering decision-making methods are proposed, and some critical problems are solved in the practical engineering management decision-making process.