In view of various quality and defect problems of Newton ring flat glass or planoconvex lens , analysisand research are caried out according to different situations, the corresponding interference patterns aresimulated, and the consistency of quality problems and interference pattern changes is analyzed. The resultsshow that the change of interference pattern is consistent with the quality problems of the device.The qualityand defects of Newton ring can be judged by analyzing the interference pattern of Newton ring. The researchresults have certain guiding significance for how to carry out surface treatment for quality and defects in actualproduction practice.