In order to solve the leakage fault occurred on a certain brand of Teflon hose, the service environment, material and manufacturing quality were analyzed. Inspection found that the internal surface of the hose lining had processing groove mark. Selecting the same batch of hose for testing, the experimental results show that the groove marks on the inner surface form the weak position of the structure, cracks occur under internal pressure and external load, leading to leakage of hose. This fault process is accelerated by complicated environment.