Abstract: The casing deformation problem is prominent during the fracturing process of shale gas wells in the Qiongzhusi Formation of the Sichuan Basin, which seriously damages wellbore integrity and affects single well productivity, and existing fracture diagnosis methods have obvious limitations in real-time performance and dynamics. To address this problem, a multi-scale discrete wavelet transform method was introduced. By taking the fracturing pressure curve as the research object, a real-time diagnosis model of fracture growth features was constructed. Combined with microseismic monitoring data, the communication status between artificial and natural fractures was judged to achieve real-time early warning of casing deformation during the fracturing process. By comparing the feature extraction effects of different Daubechies wavelet bases and decomposition levels, the db4 wavelet basis was optimized as the optimal diagnostic basis function. The middle and low frequency band of levels 4–6 was determined as the core feature frequency band, and the quantitative early warning criterion with detail energy variance and maximum absolute fluctuation amplitude as the core was constructed. Taking Well JY5HF as an example, this method was compared with the classical Nolte-Smith diagnostic method, and the effectiveness of the model was verified combined with the data of pump-down bridge plug, milling plug resistance, and microseismic monitoring results. The results indicate that the Pearson correlation coefficient between this method and the classical method reaches 0.86. It can effectively eliminate engineering noise, accurately identify different inducements of instant and delayed casing deformation, and distinguish between natural fracture communication and equipment interference signals. The research shows that this method requires no additional monitoring equipment, has low cost and strong real-time performance, and can achieve integrated evaluation of wellbore integrity involving “pre-fracturing prediction, mid-fracturing diagnosis, and post-fracturing verification”, providing technical support for the safe and efficient development of fracturing operations in shale gas wells.