Abstract: To further enhance the operational efficiency of new energy vehicles, we must pay full attention to the operational quality of the power batteries used in these vehicles. We should implement corresponding measures to address potential faults that may occur during battery use, establish a more reasonable and standardized life cycle management system, and utilize intelligent diagnostic algorithms to promptly calibrate the operating mode, thereby improving the safety performance level of new energy vehicles. This article briefly analyzes the common types of faults in new energy vehicle power batteries and discusses the application of fault diagnosis technology.