Confocal laser endomicroscopy (CLE) is a newly emerging microscopic imaging technology. It can be combined with ordinary endoscopes in cavities to generate real-time, in situ ultramicroscopic images of human body tissues by laser excitation. CLE was early applied to the endoscopic diagnosis of gastrointestinal tumors. With the development of technology, the diameter of the probe has been continuously reduced, and it has been used in the endoscopic diagnosis of urothelial tumors. During CLE imaging, a fluorescent stain is needed. In the past, bladder fluorescein was used as a fluorescent agent. Later, hexylaminolevulinic acid was used to prolong the imaging time. CLE can effectively distinguish papillary tumors, flat tumors, and erythema, as well as the boundary between normal mucosa and tumor lesions. Through special staining and laser imaging, CLE can provide real-time, high-resolution, micron-level images of the tissue to be examined. It has high accuracy and specificity, and may replace traditional pathological H&E staining to become a diagnostic tool for urothelial tumors. However, CLE is not recommended for use with fluorescent cystoscopy, and has the disadvantages of a small imaging range and reliance on stable surface contact. Thus, more advanced imaging technology, signal transmission technology, and sampling stabilization technology are required to provide support for CLE.