Abstract: Objective To investigate the clinical characteristics and related factors of cognitive impairment secondary to diffuse axonal injury(DAI) and provide clinical basis for early intervention. Methods Eighty-five patients with DAI conforming to the standard were included, and baseline information including demographic information, admission glasgow coma scale(GCS), coma time, operation,combination of other injuries, hypertension, diabetes, smoking, drinking, and nosocomial infection were collected. Montreal Cognitive Assessment(MoCA) was performed 3 months after injury to evaluate cognitive function in 85 patients with DAI. The analysis was done by t-test,χ²-test and logical regression analysis. Results Cognitive dysfunction occurred in 62 patients with DAI(72.9%). Cognitive dysfunction mainly manifested in attention, abstraction and memory(with t values respectively 9.004, 2.424, 7.423, P values below 0.001). logistic regression analysis showed that age and coma time were the risk factors for cognitive dysfunction(OR values respectively 1.842, 3.013, 95%CI values 1.211-4.323, 1.872-6.214, P values 0.034, 0.013). Conclusion Cognitive dysfunction in DAI mainly manifest in attention, abstraction and memory damage. Age and coma time are risk factors of cognitive dysfunction.