Objective To investigate the evaluation value of magnetic susceptibility weighted imaging (SWI)in patients with mild traumatic brain injury (MTBI) and the correlation between the area and number of SWI hemorrhagic lesions and GCS. Methods The clinical data of 98 patients with MTBI who were treated in the hospital during June 2012 to August 2014 were retrospectively analyzed. The detection results of conventional magnetic resonance imaging (MRI) and SWI in patients with MTBI were compared. The changes of area and number of SWI hemorrhagic lesions and clinical Glasgow coma score (GCS) were analyzed by Spearman correlation analysis and the results were recorded and analyzed. Results ①There were 76 cases (77.6%)with positive hemorrhagic lesions detected by SWI, significantly more than 55 cases (56.1%) detected by conventional MRI (P<0.05). There were 251 hemorrhagic lesions detected by conventional MRI and the median was (4.5±1.6) while there were 389 hemorrhagic lesions detected by SWI and the median was (6.8±1.7) (P<0.05). ②The area and number of SWI hemorrhagic lesions and clinical GCS were negatively correlated (P<0.05). Conclusion SWI has positive impact on improving the detection rate of hemorrhagic lesions in patients with MTBI and helping doctors accurately control the number, area and distribution of hemorrhagic lesions to improve the pertinence and effectiveness, etc. of follow-up treatment. It is worthy of clinical promotion. The area and the number of SWI hemorrhagic lesions are negatively correlated with GCS, which needs clinical attention.