Objective The MRI diagnostic data of 43 patients with plantar fasciitis confirmed by clinical diagnosis and follow-up were retrospectively studied. Methods Selection in August 2016 to August 2017 because of a foot pain clinic of 43 patients as the research object, to colour to exceed and MRI in the diagnosis of patients with diagnosed with lateral contrast and health parapodum bottom thickness of the membrane and the correlation coefficient between the reviewers. Results 43 cases of plantar fasciitis were confirmed by clinical and follow-up. Of MRI diagnosis results: 43 cases of plantar fascia around the most common soft tissue edema, 32 patients were characterized by calcaneal bone marrow edema, 17 patients were observed in the plantar fascia tendon signal change. There were significant differences in the diagnosis and treatment of the lateral and healthy side of the MRI diagnosis, and the MRI diagnosis was significantly better than the control group, and the difference between the groups was statistically significant (P< 0.05). There was significant difference in correlation coefficient between color ultrasound and MRI. MRI diagnosis was significantly better than the control group, and the difference between groups was statistically significant (P< 0.05). Conclusion Plantar fasciitis plantar fascia was observed by MRI in the diagnosis of thickness and signal change, soft tissue around the heel bone marrow edema, fascia swelling degree of change has a good diagnosis performance, clinical can be used as the preferred methods for the diagnosis of plantar fasciitis.