Objective To explore clinical application value of MRI in the diagnosis of femoral trochlear dysplasia. Methods Forty eight patients with knee pain undergoing MRI examinations were selected as research subjects, who were divided into 2 groups according to different diagnosis results, and patients in the control group were normal, 24 patients in the experimental group suffered from femoral trochlear dysplasia. Femoral tochlear spacing, lateral angle of inclination, ratio of articular surfaces of internal and external patellar trochlea, Wiberg index and classification of 2 groups of patients were observed. Results lateral angle of inclination, ratio of articular surfaces of internal and external patellar trochlea and Wiberg index of patients in the control group hit, being higher than those of patients in the experimental group (P＜0.05). Femoral tochlear spacing of patients in the experimental group being higher than that of patients control group (P＜0.05). Conclusion MRI applied for the diagnosis of femoral trochlear dysplasia delivers clinical significance, it not only can truly reflect form of femoral morphology but also generate high repeatability of measured data, it can reduce the measuring error, thereby improving the specificity and sensitivity of diagnosis at utmost extent, while MRI makes higher resolution on soft tissues of patients in the diagnosis of femoral trochlear dysplasia, it can clearly display the ligament, muscle and other soft tissue and joint surface under slight bone edema, cystic change and wear degree of articular cartilage of patients and provide detailed information for patellar joint function, being worthy of clinical application and promotion.