Abstract: Aiming at the problem of multi source information fusion, sample information is discretized and simplified with discretization algorithm based on Kohonen network and rough sets theory, and an experiential decision making table for decision making problem is established. On the basis of that, using the experiential decision making table and the relationship between rough sets theory and evidence theory, basic probability assignment and condition probability assignment of the related evidence about decision making information are calculated. Finally, according to the combination rule, the above condition probability assignment is combined, and decision making is also done according to the rules of decision making. Practical application shows that the experimental result of this method is satisfactory.