Objective To analyze the value and imaging features of digital subtraction CT angiography (DSCTA) and low field intensity MRI in the diagnosis of subarachnoid hemorrhage (SAH). Methods 85 cases of patients with SAH in the hospital from January 2014 to January 2018 were selected. All patients were given DSCTA and low field intensity MRI. The cerebral angiography (DSA) was taken as the gold standard, and the diagnostic efficacy of DSCTA and low field intensity MRI was counted, and the detection rates of SAH with different causes were counted by DSCTA and low field intensity MRI, and the detection rates of different sites of aneurysms by DSCTA and low field intensity MRI were counted, and the detection rates of different sizes of aneurysms by DSCTA and low field intensity MRI were counted. Results The diagnostic accuracy, specificity and sensitivity of DSCTA for SAH were 92.94%, 80.00% and 93.75% respectively. The diagnostic accuracy, specificity and sensitivity of low field intensity MRI for SAH were 90.59%, 80.00% and 91.25%. The detection rate of intracranial aneurysm by DSCTA was higher than that of low field intensity MRI (P<0.05). There were no significant differences in the detection rates of aneurysms of different sites and sizes by DSCTA and low field intensity MRI (P>0.05). Conclusion Both DSCTA and low field intensity MRI have high diagnostic efficacy for SAH. DSCTA can improve blood vessel contrast and remove bone structure interference, and has high detection rate of aneurysms.