The emergence of photoacoustic imaging has expanded the application of biomedical imaging technology in cells, tissues, and living organisms to monitor a variety of physiological processes in complex internal environments. Photoacoustic imaging is essentially 3-D imaging, involving three spatial dimensions. By adding time or frequency dimensions, richer tissue information can be obtained, enabling qualitative and quantitative analysis of target morphological structures and functional components. This article reviews the research progress of 4-D (3-D+time or 3-D+spectrum), 5-D (3-D+time+spectrum) photoacoustic imaging technology and photoacoustic spectral unmixing technology. and The current problems were summarized. The clinical application prospects and possible development directions in the future were predicted.