In order to reveal the mechanism and modulation characteristics of vibration and noise in scroll compressors,an experimental platform was established to simulate spindle wear faults.The signal demodulation methods were used to discuss the characteristics of vibration and noise signals,and the impact of such faults on scroll compressors were explored.By comparing with the cyclostationary analysis method,the superiority of the signal demodulation method based on time-frequency analysis and principal component analysis (DPCA) in processing scroll compressor signals was verified.Through the DPCA method,the signal modulation feature of the scroll compressor was extracted.The signal characteristics and generation mechanism under different operating conditions were discussed.The result shows that the amplitude of the modulation frequency in the principal component is enhanced by the periodically changing electromagnetic force and pressure.The vibration in the x and y directions plays a leading role in the change of noise.