To study the effects of dexmedetomidine and remimazolam tosilate on emergence agitation (EA) in adults patients in the post-anaesthetic care unit. Methods: This study is a single-center, double-blind, randomized controlled clinical trial. A total of 186 patients with EA occurring in the post-anaesthetic care unit, who met the inclusion and exclusion criteria, were enrolled and randomly assigned to the remimazolam group (R group) or dexmedetomidine group (D group). Remimazel tosilate (0.1 mg/kg) or dexmedetomidine (0.4 μg/kg) was given intravenously, respectively. If the patient did not fall asleep, the above dosage was repeated until the patient fell asleep; then continuous infusion of remimazolam tosilate (20 mg/h) or dexmedetomidine (80 μg/h) was continued for 30 minutes. During treatment, vital signs, operative time, type of surgery, numerical rating scale (NRS) score, Richmond Agitation Sedation Scale (RASS) level, 4AT score, number of medications used, onset time and awakening time were collected. On postoperative day one to three, patients underwent 4AT testing and assessment of adverse events, and hospital stay data were recorded. Results: A total of 158 cases completed the study, with 79 cases in each R group and D group. There were no significant differences between the two groups in general information (P>0.05). The number of medications used by the R group was lower than that of the D group (P<0.05), and they fell asleep faster than the D group (P<0.05), but there was no significant difference in awakening time between the two groups (P>0.05). At T2 (time of sleep onset) and T3 (10 min after continuous infusion began), the mean blood pressure (MBP) in the D group was higher than that in the R group, and heart rate (HR) was lower than that in the R group (P<0.05); at T4 (20 min after continuous infusion began), the HR in the D group was lower than that in the R group (P<0.05). There was no significant difference in the incidence of delirium relapse between the two groups (P>0.05). During treatment, the incidence of sinus bradycardia and hypertension in the D group was higher than that in the R group, while the incidence of hypotension was lower than that in the R group (all P<0.05). There were no significant differences between the two groups in re- spiratory depression, sinus tachycardia, dizziness, nausea, vomiting, catheter-related bladder stimulation syndrome, chills, and delirium (all P>0.05). Before pharmacotherapy after EA occurrence, there was no significant difference in delirium incidence between the two groups (P>0.05); however, after treatment with remimazolam or dexmedetomidine, the probability of delirium occurrence significantly decreased (P<0.05). Conclusion: Both remimazolam tosilate and dexmedetomidine have good therapeutic effects on EA occurring in the post-anaesthetic care unit, with remimazolam tosilate having a faster onset and less suppression of circulation.