Abstract: OBJECTIVE To study the methods to improve the adverse reaction of slow heart rate induced by dexmedetomidine hydrochloride, which is used for sedation after craniocerebral injury surgery. METHODS The 120 patients who had low heart rate induced by dexmedetomidine hydrochloride were randomly divided into three groups, including atropine sulfate injection group, isoproterenol hydrochloride group and dopamine hydrochloride injection group. Each group contained 40 cases. The heart rate, the goal blood pressure, arrhythmia, gastric retention, pulmonary infection, the goal heat card, neuron-specific enolase, glial fibrillary acidic protein S100B, cerebral extraction of oxygen and cerebral artery-venous oxygen content difference were observed in three groups after drug intervention, as well as the morbidity and mortality at 3 months after surgery. RESULTS After drug intervention, the compliance rate of heart rate >60 times per minute of three groups was higher. In terms of the goal blood pressure, isoproterenol hydrochloride group had a higher completion rate(minimum 97.5%), meanwhile the completion rate of the atropine sulfate injection group was slightly lower(P<0.05). The compliance rate of goal blood pressure of dopamine hydrochloride injection group was lower than other 2 groups(P<0.05), and the incidence of arrhythmia was obviously higher than other groups(P<0.05). Compared with other 2 groups, the probability of gastric retention as well as infection in atropine sulfate injection group increased significantly(P<0.05); the compliance rate of 168 h goal calories was significantly decreased. The dopamine hydrochloride injection group and isoproterenol hydrochloride group had no significant difference in gastric retention, infection and compliance rate of goal calories. There were no obvious different in cerebral oxygen metabolism, nerve function factors, mortality and disability rate at 3 months after drug intervention among the three groups. CONCLUSION Isoproterenol hydrochloride, atropine sulfate injection and dopamine hydrochloride injection can improve the cardiac slowdown caused by dexmedetomidine sedation, while isoprenaline hydrochloride has the least adverse reaction, which can be recommended for clinical application.