A total of 6 564 academic papers and 110 highly cited papers on optical imaging in biomedical field from 1990 to 2020 in Web of Science database were selected as the research objects, and the distribution characteristics, co-authors and keywords co-occurrences were analyzed by using the statistics and bibliometric software CiteSpace. Results show that photoacoustic imaging, nanoparticles, optical biopsy, Oct, deep tissue imaging, cell imaging, probes, cancer theranostics, drug delivery, carbon nanotubes and other aspects are the research hotspots in this field. Near infrared-Ⅱ spectral fluorescence imaging, semiconductor polymer nanoparticles, photoacoustic imaging, optical biopsy, tumor theranostics have become the frontier topics in biomedical optical imaging. The research in the following aspects are particularly prominent: deep tissue optical imaging, organic semiconductor materials for phototherapy and biopsy, photoacoustic imaging contrast agents and two-dimensional titanium nanosheets for multimodal imaging-guided cancer theranostics.