Ten C/ E composite pressure vessels were testing by acoustic emission technique to research the Feasibility of evaluating the craft quality and damage seriousness by t-location and the Felicity ration.In addition,the fatigue test of the C/ E compostie pressure vessels were examined by the acoustic emission technique. The results show that the acoustic emisson technique is feasible to evaluating the composite pressure vessel and t-location and fatigue test are the assistant function for evaluation.Damage of the vessel is more serious as the Felicity ratio is bigger.