Abstract: The permanent magnet synchronous machine (PMSM) finds extensive application across numerous domains due to its straightforward structure, elevated power factor, and impressive power performance. This paper delves into the fundamental operational principles and presents a simplified mathematical representation of the PMSM. Aiming at the stator faults that may occur in single or complex working conditions of PMSM, the causes and diagnosis methods of various stator faults are classified and discussed. The improvement strategies for stator fault detection and resolution are summarized, along with an overview of the applicable contexts for stator fault diagnosis methods. Each online monitoring technology for stator faults is examined individually. Lastly, the current research challenges and future directions for development are identified.