Objective To investigate the value of spiral CT in differential diagnosis of benign and malignant thyroid nodules. Methods A total of 86 patients with thyroid nodular diseases who were admitted to the hospital during the period from February 2016 to February 2018 were selected as subjects. All patients underwent spiral CT examination. With pathological results as the golden standard, the value of spiral CT in differential diagnosis of benign and malignant thyroid nodules was evaluated. Results The sensitivity, specificity and accuracy of multi-slice spiral CT in the diagnosis of benign and malignant thyroid nodules were 88.13%, 81.48% and 86.05%, and the Kappa value was 0.682, respectively. The proportions of regular shape, clear edges and calcified strips in the benign nodule group were significantly higher than those in the malignant nodule group (P<0.05), but there was no significant difference between the two groups in the location of lesions or the proportion of cystic change (P>0.05). The proportion of homogeneous enhancement in the benign nodule group was significantly higher than that in the malignant nodule group (P<0.05), while the proportions of residual ring-like enhancement and peninsulalike enhancement were significantly lower than those in the malignant nodule group (P<0.05). Conclusion The diagnostic efficiency of spiral CT is high for benign and malignant thyroid nodules. The spiral CT imaging features and enhancement features can be used to distinguish benign and malignant thyroid nodules.