Objective To evaluate the effect of shear wave elastography (SWE) combined with CT in the evaluation of chronic ankle instability (CAI). Methods Retrospective analysis was made on 50 patients with unilateral chronic ankle instability admitted to Chengde Central Hospital from October 2020 to October 2021. The patients were divided into healthy side group and affected side group according to their healthy side and affected side. CT and SWE were adapted to examine the medial head of gastrocnemius muscle and soleus muscle on the healthy side and the affected side of CAI patients. CT values (Hu), Young's modulus (Kpa) and other parameters were measured. Results There was a significant positive correlation between SWE and CT values in the evaluation results of chronic ankle instability muscles (pearson correlation coefficient of gastrocnemius muscle=0.661, P<0.001; pearson correlation coefficient of soleus muscle=0.726, P<0.001). Young's modulus measured by SWE gradually decreased, and CT value also gradually decreased, the difference was statistically significant (P<0.001). Conclusion SWE technique and CT examination are correlated in the evaluation of chronic ankle instability muscle, and the changes are consistent.