The traditional airport runway foreign object automatic detection system has a single monitoring method for foreign objects, and the multi technology system monitoring method is the future development trend. However, when multiple technology systems monitor, the fusion algorithm is prone to evidence conflict and failure. This article proposes a multi-sensor fusion algorithm based on the improved D-S evidence theory to address the issue of evidence conflict and failure. The fusion algorithm introduces the cross-correlation factor between various evidence, To achieve better integration of multi technology systems in complex situations.