Lacrimal duct obstruction is a common disease in ophthalmology, secondary infection is chronic dacryocystitis, can cause great impact on human health and life, drug treatment is ineffective, must be implemented surgery. In the past, lacrimal duct examination methods are often used to indirectly understand the situation of the lacrimal duct, but the contrast agent is viscous, and sometimes it is necessary to repeatedly inject the contrast agent from the tear point for several times to obtain a clear image, in recent years, the application of magnetic resonance imaging of the lacrimal duct is we can more clearly understand the direction of the lacrimal duct, the width and narrow, the site of broken flow, but can not directly observe the internal situation of the lacrimal duct. The only surgical method people use to treat dacryocystitis is lacrimal sac removal, and it was not until 1904 when Delaney [1] invented the external dacryocystorhinostomy (EDCR) that the treatment of dacryocystitis was possible to achieve functional recovery, and with the improvement of clinical techniques, the success rate of nasal lacrimal sac anastomosis reached more than 90%, but there is easy bleeding, leaving facial scarring, possible displacement of the tear dots However, there are disadvantages such as easy bleeding, facial scarring, possible displacement of the tear point, damage to the medial canthus ligament and partial damage to the orbicularis oculi. In recent years, lacrimal duct exploration and laser lacrimal duct exploration are commonly used, which is an ideal treatment method with less damage, less bleeding and no scar on the skin surface, and its success rate is up to 84.1%. However, due to the inability to see the internal course of the lacrimal tract directly, a false channel is often formed, resulting in surgical failure. In recent years, with the invention and development of electronic endoscopy technology, endoscopy has begun to be widely used in various fields of medicine, especially now the endoscope is very dexterous, the diameter of the tube is very small, can reach any part of the tear duct, through the magnification of the monitor to clearly observe the small changes in the tear duct, with the use of laser and micro electric drill, so that the examination and treatment of tear duct disease has been significantly changed, its advantages The advantages are: on the one hand, the site of lacrimal duct obstruction and the lumen can be observed through the endoscope; on the other hand, simultaneous treatment can be performed under direct vision through the working channel, which makes the diagnosis of lacrimal duct disease more accurate and fine, while the choice of surgical method is more purposeful. The lacrimal endoscope is mainly designed for the diagnosis and treatment of lacrimal tract disease, divided into a two-channel probe for examination, diameter 0.8mm, the probe contains two tubes, one tube through the 0.6mm diameter endoscope lighting and camera fiber, the other tube through the 0.2mm diameter connected to the flushing device, treatment with a three-channel probe, diameter 1.1mm, the probe contains three tubes, one tube through the 0.6mm diameter endoscope One tube passes through the 0.6mm diameter endoscope illumination and camera fiber, the other tube passes through the 0.2mm diameter flushing device, and the middle channel is the 0.4mm diameter working channel, which can be passed through the laser fiber or micro-ring drill. In this way, the obstruction can be treated under direct vision, avoiding damage to normal tissues and the formation of pseudo-tracts, effectively preserving the siphoning effect of the tear duct itself, minimizing the impact on the tear sac and other parts of the lacrimal pump function, with the advantages of less tissue damage, less bleeding, faster postoperative recovery, simple operation, and short duration, which can be widely used in clinical examination and treatment. In our examination of previous cases after laser or exploratory surgery alone, we found that white fibrous material often remained in the lumen of the lacrimal duct, which was free at one end and unobstructed when flushed, but bacteria and secretions were easily attached, which might be the source of postoperative reobstruction. It is difficult to remove it cleanly and restore smooth canal lumen by blind treatment alone. Under the direct view of endoscope, the fibers can be clearly seen and completely removed, which effectively keeps the normal duct open and avoids large damage to the lacrimal mucosa, and can better avoid the formation of postoperative scars and the occurrence of reobstruction, which is the most advanced treatment method so far.