Objective: To explore the influence of ultrasound-guided axillary brachial plexus block anesthesia on block analgesia status in children with distal ulna and radius fractures in emergency room. Methods: A total of 106 children with distal ulna and radius fractures were selected as research subjects. According to different reduction methods of fractures, the children were divided into control group (n=36, routine manipulation reduction) and painless treatment group (n=70, ultrasound-guided axillary brachial plexus block anesthesia manipulation reduction). The children in painless treatment group were further divided into group A (n=35, 1.0% lidocaine) and group B (n=35, 0.8% lidocaine) according to the different concentrations of lidocaine used. The block onset time, duration of analgesia and success rate of block were compared between group A and group B. The scores of Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) before reduction (T0), during reduction (T1) and at 1 h after reduction (T2), the excellent and good rate of manipulation reduction, satisfaction of medical staff, satisfaction of parents and occurrence of adverse reactions were compared among the three groups. Results: The onset time of block in group A was shorter than that in group B (P0.05). At T1 and T2 the CHEOPS score in group A and group B was lower than that in control group (P 0.05). There was no statistically significant difference in the incidence of adverse reactions among group A, group B, and the control group (P>0.05). Conclusion: In emergency room environment, the application of ultrasound-guided brachial plexus block in children with distal radius and ulna fractures is an efficient and safe analgesic strategy, which can improve the quality of reduction and the satisfaction of both doctors and patients. 0.8% lidocaine is sufficient to meet the analgesic needs of manipulation reduction.