In order to investigate the effects of Dexmedetomidine (DEX) on postoperative anesthesia recovery time and consciousness function in elderly patients with laparoscopic colorectal tumors, 40 patients (20 in the control group and 20 in the DEX group) were selected. The DEX group was intravenously pumped at a rate of 0.8 μg/kg/h for 10 min and then continuously pumped at a rate of 0.3 μg/kg/h until 40 min before the end of the operation. The two groups were given the same amount of normal saline, with the same way of anesthesia. The results showed that the visual analog scale (VAS) score of pain in the two groups decreased signally. Compared with the control group, the inflammatory factors tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and macrophage inflammatory protein (MIP-2) in the DEX group were remarkably decreased at T1 and T2 stages, with a considerable difference ( P < 0.05 ). One month after the auxiliary diagnosis of colorectal tumor, no clear nodular, irregular shape patches, or patchy diffuse limited points were found, which indicated that the whole tumor had been removed. In summary, DEX could improve postoperative cognitive function in elderly patients who underwent the laparoscopic radical resection of colon cancer, and its mechanism was related to the reduction of inflammatory factors. Therefore, the anesthesia intervention with DEX during the operation had a positive significance for tumor resection.