With the rapid development of science and technology, information collection and fusion tend to be diversified and complicated. A single sensor can no longer meet the demand. Therefore, multi-sensor information fusion technology begins to be widely used in all walks of life, and improves the accuracy and integrity of information processing. The multi-sensor information fusion technology is introduced from the aspects of concept, structure and classification as well as the research and practical application of key algorithms in this paper, and the development trend and future prospect of this technology are summarized.