Objective: To observe the application effect of shear wave elastography in chronic low back pain patients. Methods: 65 chronic low back pain patients (observation group) who were admitted to our hospital from September 2022 to December 2023 were selected, and 65 healthy volunteers (healthy group) who underwent physical examination in our hospital during the same period were selected.All subjects underwent ultrasound examination,The thickness and cross-sectional area of bilateral skeletal muscles (multifidus muscle, erector spinae muscle and transverse abdominal muscle) were obtained, and shear wave velocity (SWV) value of skeletal muscles was measured under SWE mode.The bilateral skeletal muscle thickness, cross-sectional area and SWV value of the healthy group and the observation group were observed and compared. The repeated measurement reliability (ICC) of ultrasound operation was analyzed, and the receiver operating characteristic (ROC) curve was drawn to evaluate the efficacy of different tests in the diagnosis of chronic low back pain. Results: Compared with healthy group, the thickness of bilateral multifidus muscle, erector spinae muscle and transverse abdominal muscle in observation group decreased, and the difference was statistically significant (P<0.05). The cross-sectional area of bilateral multifidus and erector spinae in observation group was smaller than that in healthy group, and the difference was statistically significant (P<0.05). The thickness and cross-sectional area of bilateral multifidus, erector spinae and transverse abdominal muscle were compared within same group, there was no statistically significant difference (P>0.05). SWV values for bilateral multifidus, erector spinae and transverse abdominal muscle were compared within same group, there was no statistically significant difference (P>0.05). The SWV values of left and right multifidus, transverse abdominal muscle and erector spinae in observation group were higher than those in healthy group (P<0.05). The consistency of the thickness and cross-sectional area of the multifidus and erector spinae measured by two ultrasound physicians was good (all ICC values>0.740, P<0.001), and the consistency of the thickness of the transverse abdominal muscle and the SWV value was excellent (ICC value= 0.954, 0.964, P<0.001). There was no significant correlation between the thickness and cross-sectional area of multifidus and erector spinae and SWV value (all P>0.05). There was no significant correlation between the thickness of transverse abdominal muscle and SWV value (P>0.05). ROC analysis showed that, when the thickness, cross-sectional area and SWV value of multifidus muscle were 1.86cm, 5.69cm2 and 2.27kPa respectively, the thickness, cross-sectional area and SWV value of erector spinae muscle were 2.06cm, 5.31cm2 and 2.15kPa respectively, and the thickness and SWV value of transversus abdominis muscle were 0.30cm and 2.09kPa, the area under the curve (AUC) of ultrasound SWE in the diagnosis of chronic low back pain was higher than that of two-dimensional ultrasound examination (thickness, cross-sectional area). The AUC of SWE combined with two-dimensional ultrasound examination in the diagnosis of chronic low back pain was 0.941 (95%CI: 0.000-1.000), the sensitivity was 87.80%, and the specificity was 95.55%, which was better than single SWE and two-dimensional ultrasound examination (thickness, cross-sectional area) (P<0.05). Conclusions: On the basis of two-dimensional ultrasound examination,combining SWE examination can further reflect the involvement of skeletal muscle in chronic low back pain patients, and the combine detection of two has better diagnostic efficacy for chronic low back pain patients.