Objective To analyze the imaging findings of mental disorders after craniocerebral injury. Methods A total of 63 patients with mental disorders after craniocerebral injury who were admitted to our hospital between August 2014 and September 2016 were selected as the study subjects. All patients were examined by CT and MRI. The detection rate and imaging findings of CT and MRI in abnormal sites of craniocerebral injury were analyzed. The diagnostic sensitivities, specificities and accuracies of CT and MRI were compared, and the value of Rotterdam CT score in evaluating the prognosis of craniocerebral injury was evaluated. Results MRI detected a total of 116 abnormal parts and CT detected 87 abnormal parts. The detection rate of MRI (80.0%) was higher than that of CT (60.0%) (P<0.05). CT examination showed severe contusion and laceration, brain edema and brain swelling, lateral fissure and brain cistern hematocele and traumatic subarachnoid hemorrhage in patients with moderate craniocerebral injury, little right frontotemporal subdural hematoma and left ventricle posterior horn hematocele in patients with severe craniocerebral injury. MRI showed signal on T2WI in patients with cranial plate fractures, equal T1 and long T2 signal in scalp injury. MRI showed subcortical patchy abnormal signals in patients with brain stress ipsilateral or contralateral contusion, low signal on T1WI, high signal on T2WI and homogeneous signal. The sensitivity and specificity showed no significant differences between CT and MRI in the diagnosis of mental disorders after craniocerebral injury (P>0.05). The accuracy was lower than that of MRI (61.90% vs 79.37%) (P<0.05). Rotterdam CT score showed significant differences between patients with mild, medium and severe disease (P<0.05). Conclusion Both CT and MRI are of certain value in the diagnosis of mental disorders after craniocerebral injury, and the accuracy of MRI is relatively higher. Rotterdam CT score can be used to assess the prognosis.