Objective To explore MRI image analysis of the clinical diagnostic value of knee joint disease. Methods From January 2013-January 2015 of knee joint disease patients admitted in our department in 70 cases were randomly selected as the research object. The patients were first given with MRI (observation group), then X-ray examination (control group). Observed and compared two groups of diagnostic coincidence rate. Results The observation group's joint effusion 11.43% 11.43%, 15.71% thinning of the cartilage and bone defect, half leaf plate damaged 32.86% detection rate was significantly higher than that of control group were 1.43%, 2.86%, 10.00% and 17.14%, respectively. Which were statistically significant differences (P<0.05). Observation group's knee lesion detection sensitivity 84.29%, specificity 91.43% was higher than the control group of 68.57%, 75.71%. Which were statistically significant differences (P<0.05). Observation group's knee lesions single lesion inspection rate was more than 30.00%, lesions were higher than in control group of 14.29%, 64.29% and 14.29%. Observation group's knee lesions of missed diagnosis and misdiagnosis rate were 0% 2.86% lower than the control group of 12.86%, 18.57%. Conclusion MRI in the diagnosis of knee joint disease sensitivity, high specificity, accurate diagnosis of knee lesion is beneficial to provide the correct treatment, improve the prognosis, is worthy of attention.