Objective To evaluate and compare the anesthetic efficacy and safety profiles of three ultrasound-guided nerve block regimens for clavicle fracture surgery： C5 nerve root block （C5-NRB） combined with cervical nerve pathway block （CNPB）， C5 nerve root block paired with superficial cervical plexus block （SCPB）， and interscalene brachial plexus block （ISBPB） combined with SCPB. Methods By using a random number table， 90 patients scheduled for clavicle fracture surgery （ASA Ⅰ-Ⅱ） were randomly allocated to three groups （30 patients per group）： the C5C group （C5-NRB combined with CNPB）， the C5S group （C5-NRB paired with SCPB）， and the IS group （ISBPB coupled with SCPB）. All nerve blocks were performed under ultrasound guidance with 0.4% ropivacaine. In the C5C group， 5 mL of the anesthetic was injected at the C5 nerve root， followed by 10 mL within the cervical nerve pathway. The C5S group underwent a C5 nerve root block plus a superficial cervical plexus block （10 mL）. In contrast， the IS group received 10 mL each for the interscalene brachial plexus block and the superficial cervical plexus block. After the nerve block was completed， the cutaneous sensory level over the clavicular surgical field was verified using the pinprick technique， and the pain intensity was documented simultaneously. Both the onset time of the sensory block and the intraoperative requirements of sufentanil were recorded. The Modified Bromage Score （MBS） was used to assess the motor function of the affected-side upper limb at the end of surgery and at 6 and 12 hours postoperatively. Diaphragmatic excursion alterations during deep breathing and changes in blood pressure were monitored during the operation. The occurrence of adverse events， including local anesthetic toxicity， stellate ganglion block， recurrent laryngeal nerve involvement， ipsilateral phrenic nerve paralysis， and puncture pain， was systematically recorded throughout the perioperative period. Results The onset of block in the C5C group was significantly faster than that in the C5S and IS groups （P < 0.05）. The intraoperative sufentanil requirements in the C5C group were significantly lower compared to those in the C5S group （P < 0.05）， but there was no statistically significant difference compared to the IS group. Regarding the preservation of motor function， significantly higher MBS scores were recorded at 6 and 12 hours after surgery in the C5C and C5S groups than in the IS group （P < 0.05）. Moreover， the incidence of phrenic nerve block was markedly reduced in both the C5C and C5S groups compared with the IS group （P < 0.05）. Conclusions The combination of ultrasound-guided C5 nerve root block and cervical nerve pathway block offers a regional anesthetic approach with a rapid onset， analgesic effectiveness， and motor sparing for clavicle fracture surgery. Moreover， it significantly reduces the risk of phrenic nerve block. This technique exhibits superior clinical efficacy and safety.