Single-pixel imaging is a new imaging technique which can obtain image information through a single-pixel detector without the ability of spatial resolution. Compared with the traditional "what you see is what you get" imaging technique, single-pixel imaging has a series of advantages, such as high sensitivity, anti-interference and high resolution. It has shown broad application prospects in remote sensing detection, national defense military, biomedicine and other fields. In recent years, with the improvement of computing capability and the development of optoelectronic devices, single-pixel imaging has attracted more and more attention from researchers. The history of single-pixel imaging was briefly reviewed and the research progress of single-pixel imaging in basic principles, modulation matrix design and image reconstruction algorithms was introduced in detail. In addition, some application scenarios and prospect development trends in the future were summarized.