Abstract: In order to explore the interlocking and stopping factors of decarbonization lean liquid pump in LNG plant, the operation conditions are comprehensively analyzed and used to provide guidance for the next improvement. Operation conditions of Hubei 5×10⁶ m³/d LNG plant localization demonstration project relating equipments are collected for many years. Surmmaries for operation problems of lean liquid pump are deiscribed and the width of problem analysis is enlarged. The analytic hierarchy process is used for quantitative characterization of specific events and the related issues are weighed. The research shows that mathematical model with analytic hierarchy process(AHP) can make full use of current information for problem analysis. Fuzzy qualitative interlock shutdown situation can be changed effectively to science weight to provide guide analysis and the concrete plans for corresponding problems. Decision-making bottlenecks caused by analyzing data are eliminated to reduce economy risks for purchasing blindly and replacement of spare parts, and to improve the management level. The interlocking causes of machine and pump caused by temperature, vibration and instrument damage are intersecting, which can not only be triggered of interlocking by single but also be promoted by each other, and can lead to the shutdown of the pump. Due to the complexity of technical analysis and the difficulty of operation management, the current improvement measures can only solve problems partially or temporarily, and it takes time to verify whether there are defects in the future. In order to ensure the smooth production of the factory, regular stop pump failure inspection and maintenance are not allowed. It is necessary to thoroughly check the operating conditions of the equipment during the downtime maintenance, root out the problems and switch maintenance according to the operating time during normal production.