Objective To explore the value of 18F-fluorodexyglucose (18F-FDG) positron emission computed tomography (PET/CT) combined with shear wave elastography (SWE) in the diagnosis of benign and malignant thyroid nodules. Methods The clinical data of 87 patients with thyroid nodules admitted to our hospital between January 2016 and January 2018 were analyzed retrospectively. All patients were diagnosed by pathological examination, and were given 18F-FDG PET/CT and SWE after admission. The results of pathological examination were taken as "gold standard" to evaluate the diagnostic value of two methods and combined examination in the diagnosis of benign and malignant thyroid nodules. Results Of the 87 patients with 114 thyroid nodules, 81 cases (71.05%) were malignant nodules and 33 cases (28.95%) were benign nodules. The diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 80.25% (65/81), 66.67% (22/33), 76.32% (87/114), 85.53% (65/76) and 57.89% (22/38) respectively by 18F-FDG PET/CT, and were 85.19% (69/81), 72.73% (24/33), 81.58% (93/114), 88.46% (69/78) and 66.67% (24/36) by SWE check, and were 91.36% (74/81), 84.85% (28/33), 89.47% (102/114), 93.67% (74/79) and 80.00% (28/35) by the combined examination. There was no significant difference in the diagnostic sensitivity, specificity, positive predictive value and negative predictive value among the three examination methods (P>0.05), but compared with single examination, the above indicators by combined examination were significantly increased, and the accuracy rate showed combined inspection>SWE>18F-FDG PET/CT. (P<0.05). Conclusion Both 18F-FDG PET/CT and SWE have high diagnostic value for benign and malignant thyroid nodules, and each has its own advantages. The combination of the two can improve the diagnostic accuracy significantly.