To summarize the value of multislice spiral CT (MSCT) in the differential diagnosis of thick-wall gallbladder carcinoma (TWGC) and chronic cholecystitis (CC), the clinical data of 36 patients with TWGC and 60 patients with chronic cholecystitis who were treated in our hospital from January 2017 to May 2021 were retrospectively analyzed, and the CT image features and diagnostic accuracy of the patients were summarized. Compared with the CC group, the proportions of disruption of gallbladder mucosa line, blurred gallbladder outline, high obstruction of biliary tract, lymphomegaly, adjacent invasion, peritoneal effusion, wall nodules, and the gallbladder wall thickness in the TWGC group were higher, with statistical significance ( P < 0.05). Thirty-four patients with TWGC and 62 patients with chronic cholecystitis were diagnosed by MSCT. The sensitivity and specificity of MSCT in diagnosing TWGC were 86.11% and 95.00%, respectively. The positive likelihood ratio was 17.222 and the negative likelihood ratio was 0.1462. The positive prediction rate was 91.18%, the negative prediction rate was 91.94%, and the correct rate was 91.67%. MSCT can show the characteristic difference between TWGC and chronic cholecystitis, which can be used for differential diagnosis.