Target detection and recognition technology is a popular research field in image information processing technology. How to maturely apply this technology to land battlefields with complex backgrounds is an urgent pain point to be resolved. This paper first introduces the main factors affecting the performance of target detection and recognition under complex background conditions of land battlefields and analyzes the complexity, diversity, and uncertainty of the target background of land battlefields. Then, it reviews the research status of target recognition algorithms. Furthermore, it expounds on the key technologies of target detection and recognition under complex backgrounds, including multispectral complex target detection, automatic target recognition, dim and small target detection, and multi-channel heterogeneous information fusion. Finally, this paper predicts the tendencies of target detection and recognition technology in land battlefields.