Objective To investigate clinical diagnosis value of CT and MRI on early ischemic necrosis of femoral head. Methods Fifty patients with early ischemic necrosis of femoral head admitted and treated by the outpatient department of orthopaedics and inpatient department of the Hospital from January, 2014 to January, 2015 treatment were selected as research subjects, all patients underwent CT (55 cases in the control group) and MRI (55 cases in the research group) examination and diagnosis, the research approach of multi-center comparative analysis was implemented to assess the accuracy, sensitivity and specificity of two examination methods. Results Major symptom of CT on patients with ischemic necrosis of femoral head was "crescent sign". Major symptom of MRI was the "string sign", the necrosis area showed abnormal signals with different degrees of T1WI and T2WI. The statistical analysis differences in the accuracy, sensitivity and specificity of diagnosis on patients in two groups were significant (P<0.05). Conclusion MRI is capable of early diagnosis on ischemic necrosis of femoral head with higher accuracy, specificity and sensitivity. MRI diagnosis should be adopted for early pathology diagnosed to be negative via CT in order to make clear diagnosis and provide scientific and reasonable treatment for patients.