Terahertz (THz) waves are ideal for biomedical imaging because of its natural non-ionization properties, sensitivity to moisture, and penetration depth in biomedical tissues. The THz quantum cascade laser (QCL) has advantages of high power, good-quality spot, fast modulation rate, and tiny size. Compared with traditional biomedical imaging systems, the biomedical imaging systems based on THz QCL have a superior signal-to-noise ratio, higher imaging resolution, faster imaging speed, and more compact structure. This study reviewed the progress on the research of biomedical imaging systems based on THz QCL. Furthermore, this study also summarized the advantages of THz bioimaging, THz QCL biomedical imaging, biomedical imaging systems, and biomedical imaging goals. Moreover, the direction of future developments is viewed.