Permanent magnet synchronous motors (PMSMs) are widely utilized in the field of manufacturing and production due to their notable advantages such as simple structure,stable operation,high efficiency,and diverse configurations. Operating under conditions with variable speeds and load fluctuations,PMSMs inevitably experience various faults,including bearing faults,eccentricity faults,demagnetization faults,and interturn short-circuit faults. An overview of common fault types in PMSMs is provided in this paper and the existing researches on signal-based condition monitoring methods in the field of automation for the detection and diagnosis of electrical and mechanical faults are summarized. Subsequently,diagnostic methods are summarized,and their strengths and limitations are analyzed,discussing the pros and cons of different signal processing approaches in application. Finally,considering the current state of research,the challenges and future directions in the monitoring and diagnosis of PMSM faults are discussed.