Objective To study the online testing and feedback of print image quality. Methods Machine vision inspection technology, digital image processing technology and DP method were used to segment and match standard proofs and defective proofs. According to the type of image resolution and the desired detection accuracy, the type of image segmentation method was designed, thereby the detection and analysis of the color information was performed. Secondary identification defect classification technology was used to classify the defects and display the corresponding defect types, thereby the overall quality of the printed product was improved. Results Compared with the traditional printing quality testing, higher inspection speed and precision were achieved. Conclusion Combined with defect characteristics based on the DP method, print defects can be detected quickly and accurately.