Objective To explore the effect of dexmedetomidine combined with nutritional intervention on cognitive function recovery and prognosis of patients with severe cranial traumatic brain injury in ICU. Methods A total of 100 patients with severe cranial traumatic brain injury from February 20, 2016 to December 30, 2016 in our hospital ICU were selected and randomly divided into two groups, the control group were given nutrition intervention, the experimental group combined with dexmedetomidine and nutritional intervention. Results The difference of PACHE Ⅱscore, GCS score, mechanical ventilation time, and hospitalization timebetween the 2 groups was statistically significant (P<0.05); The recovery of cognitive function in the experimental group was better than that in the control group (P<0.05). Conclusion The value of dexmedetomidine and nutritional intervention in patients with severe cranial traumatic brain injury in ICU is higher.