Objective To explore the CT imaging manifestations and the application value of CT examination in the clinical differentiation and diagnosis of patients with atypical thoracic sarcoidosis. Methods 73 patients with thoracic and lung lesions treated in our hospital from May 2012 to May 2015 were taken as the research objects. The results pathological examination were taken as the final results. All patients underwent multislice spiral CT scanning. The CT imaging manifestations of patients with atypical thoracic sarcoidosis were summarized and the confirmed results were compared with the results of pathological examination to clearly identify the differential and diagnostic value of CT. Results The main CT imaging manifestation of patients with atypical thoracic sarcoidosis was intrathoracic lymphadenectasis, usually with pulmonary infiltration manifestations, such as ground glass shadow, nodular shadow and irregular linear opacities, complicated with spot-like calcification, clear enlarged lymph nodes boundaries, apparently homogeneous enhancement. A total of 58 cases of atypical thoracic sarcoidosis, 2 cases of tuberculosis, 2 cases of lymphoma and 1 case of metastatic tumor were diagnosed, and the remaining 10 cases were misdiagnosed or missed diagnosed. The accuracy rate in the diagnosis of atypical thoracic nodules was 86.6% (58/67). The main enhancement mode of patients with atypical thoracic sarcoidosis was homogeneous, reaching 65.7%. CT enhancement of metastatic tumor also was homogeneous enhancement, which needed to be identified. The most CT enhancement degree of patients with atypical thoracic sarcoidosis was obvious enhancement, reaching 64.2%, whiloe there was no obvious enhancement in tuberculosis, lymphoma and metastatic tumor, et al, which were easy to identify. Conclusion The application of CT in patients with atypical thoracic sarcoidosis can make the lesions observed more clearly, which is conducive to the localization, differentiation and diagnosis of sarcoidosis, with great clinical value.