The invention discloses a machined part surface 
chatter mark defect detection method which comprises the following steps: measuring acceleration response signals of a cutter along the 
horizontal and vertical directions of a 
machine tool in the current 
machining process of a part, filtering cutter-pass 
harmonic components in the acceleration response signals, extracting 
wavelet entropy characteristics reflecting 
machining instability intensity in the acceleration response signals, and calculating the 
chatter mark defect of the machined part, recording the 
wavelet entropy characteristics as a vibration characteristic; inputting the vibration characteristics into a pre-trained 
flutter detection model, and judging the 
flutter state of a current weak-rigidity 
machining system for machining thepart; and if the part is in the 
flutter state, the current machining surface of the part has the 
chatter mark defect. After each part is machined, according to the accuracy of the current flutter detection model, on the basis of an existing flutter detection model, an 
incremental learning mode is adopted, continuously-accumulated actual measurement vibration information is utilized, some information which can have adverse effects on judgment precision is eliminated step by step, and therefore the accuracy of the flutter detection model is improved, and the accuracy of the flutter detection model is improved. And the detection precision of the 
machined surface chatter mark defects is high.