Abstract: Objective To explore the value of diffusion tensor imaging(DTI) in evaluating the prognosis of mild traumatic brain injury(mTBI) patients with different social support. Methods From January 2016 to January 2018, 99 patients with mTBI in the departments of emergency surgery and neurosurgery of the Second Affiliated Hospital of Wenzhou Medical University, were divided into high social support group(54 cases) and low social support group(45 cases) according to their social support rating scale(SRSS) score(>20). The scores of Easy Mental State Examination Scale(MMSE) and Montreal Cognitive Assessment Scale(MoCA) were measured by DTI. Anisotropic score(FA) and apparent diffusion coefficient(ADC) were recorded and compared. Results ①The scores of MMSE and MoCA in patients with high social support were higher than those in patients with low social support(all P<0.05); ②The FA values of frontal lobe, medial temporal lobe and knee of corpus callosum in patients with low social support decreased significantly(all P<0.05). ③The ADC values of left white matter of frontal lobe, right white matter of frontal lobe, left white matter of temporal lobe and right white matter of temporal lobe in patients with low social support were higher than those in patients with high social support(all P<0.05). Conclusion The cognitive status and cognitive function of mTBI patients with different social support levels are significantly different, and the FA and ADC values of DTI are also partly different. Cognitive impairment is closely related to the impairment of white matter in frontal lobe, temporal lobe and corpus callosum.