Objective To investigate the effect of Dexmedetomidine combined with Ropivacaine intermuscular sulcus nerve block on the analgesic effect and bispectral index (BIS) value of patients. Methods A total of 83 patients undergoing upper arm surgery admitted to Huairou District Hospital of Traditional Chinese Medicine in Beijing from April 2019 to March 2021 were selected as the research objects, and they were divided into observation group (41 cases) and control group (42 cases) by random number table method.Control group was given Ropivacaine combined with placebo block, and observation group was given Ropivacaine combined with Dexmedetomidine block.The onset time of analgesia, duration of analgesia, onset time of exercise block and recovery time of exercise were compared between the two groups, and the changes of BIS values at different intraoperative time were compared between the two groups. Results There was no significant difference in the onset time of analgesia between the two groups (P＞0.05).The duration of analgesia in observation group was longer than that in control group, and the difference was statistically significant (P＜0.05).There was no significant difference in the effective time of movement block between the two groups (P＞0.05).The exercise recovery time of observation group was longer than that of control group, and the difference was statistically significant (P＜0.05).BIS values of T1-T5 in observation group were lower than those in control group, the differences were statistically significant (P＜0.05).In the observation group, BIS value at T1 was lower than T0, BIS value at T2 was lower than T1, and BIS value at T4 was higher than T3, the differences were statistically significant (P＜0.05).In the control group, BIS value at T2 was lower than T1, BIS value at T3 was lower than T2, BIS value at T4 was higher than T3, and BIS value at T5 was higher than T4, the differences were statistically significant (P＜0.05). Conclusion Dexmedetomidine combined with Ropivacaine intermuscular sulcus nerve block can prolong the patient's exercise recovery time and the duration of analgesia, and improve the patient's anesthesia effect.