Objective To compare the detection rate and clinical value of dual-source CTA and 3D-DSA for intracranial small aneurysms. Methods Retrospective analysis of 35 cases of suspected intracranial small aneurysms in our hospital from July 2015 to December 2017,comparison and analysis of the double-source CTA and DSA examination data, and record the location, size, number and neck width of small aneurysms, to analyze the sensitivity, specificity and YouDen Index of the diagnosis of intracranial small aneurysms. Results 30 patients were confirmed with intracranial small aneurysms, dual source CTA diagnosed 31 small aneurysms in 29 patients, in all aneurysms, the results of 30 aneurysms were consistent with DSA, there was no significant difference between CTA and DSA (P>0.05),no statistical significance. The location, size, number and neck width of the aneurysms were basically consistent with that of DSA. Conclusion Dual-source CTA has good sensitivity and specificity for diagnosing intracranial small aneurysms, to compare with DSA, Dual-source CTA is relatively noninvasive, fast, low risk and low cost, it can be the preferred method for screening intracranial small aneurysms. Diagnosis conclusion is of great significance for further clinical treatment.