To analyze the effect of dexmedetomidine combined with tumescent anesthesia in cosmetic plastic surgery. Methods A total of 106 patients undergoing cosmetic plastic surgery admitted to our hospital from November 2022 to November 2023 were randomly divided into reference group and experimental group, with 53 patients in each group. The reference group was treated with propofol combined with tumescent anesthesia, and the experimental group was treated with dexmedetomidine combined with tumescent anesthesia. The vital signs and clinical indicators of the two groups were compared. Results The MAP, RR and HR levels of the two groups at T1 were lower than those at T0, and the MAP and HR of the experimental group at T2 and T3 were lower than those of the reference group, and the RR was higher than that of the reference group (P <0.05). The dosage of sufentanil in the experimental group was less than that in the reference group, the VAS score, the incidence of body movement or pain and respiratory depression were lower than those in the reference group, and the awake time was shorter than that in the reference group (P <0.05). Conclusion The application of dexmedetomidine combined with tumescent anesthesia can better stabilize the hemodynamics for patients in cosmetic plastic surgery, reduce the dosage of sufentanil, improve the anesthetic effect and safety, and is worthy of clinical application.