Abstract: The neutron tube is a key component with a wide range of use. However, the reliability level of domestic neutron tube is still far from that of foreign countries, and it is difficult to meet the need of various industries. In this paper, the main failure mode of neutron tube was analyzed. The fuzzy comprehensive evaluation and analytic hierarchy process were used to evaluate the neutron tube failure in multiple stages, and the risk of neutron tube failure was evaluated. The results show that the overall risk of neutron tube failure is medium, and the top three components of failure risk are target, D-T storage and acceleration pole. The focus on the failure modes, such as target helium release, target membrane oxidation, partial damage of the D-T storage, porcelain tube break, unstable accelerating and focusing of the acceleration pole, should be paid during design and use.