Aiming at the research of multi-sensor fusion of filling system, in order to meet the accuracy and reliability requirements of the fusion, an improved adaptive weighted fusion algorithm is presented. The key point of weighted fusion is the accurate calculation of fusion weights. The research on fusion weights calculation is summarized and analyzed, a modified evidence distance from D-S evidence theory is used to calculate the distance of test data, and fusion weights can be obtained. General example and typical example of filling system is used to test the proposed fusion algorithm. The example show that the proposed fusion algorithm takes on strong robustness and good fusion result, and it has theoretical and practical significance.