Objective To clearly define and describe the difference of analgesic actions and side effects between dezocine and parecoxib sodium in video-assisted thoracic surgery (VATS) lobectomy. Methods Ninety patients underwent thoracotomy (lobectomy) and were hospitalized in the Department of Thoracic Surgery, West China Hospital, Sichuan University between August 2015 and January 2016. Patients were randomly divided into two groups including a parecoxib sodium group (a PG group, 43 patients) and a dezocine group (a DG group, 47 patients). We analyzed the occurrence of side effects in the two groups, as well as other outcomes including visual analogous scores and location of the pain et al. Results The occurrences of nausea, vomit and abdominal distention in the PG group (9.30%, 2.33%, 13.95%) were significantly lower than those of the DG group (25.53%, 17.02%, 40.43% , P=0.046, P=0.032, P=0.009) in the early period after operation. Pain scores at the postoperative 12 h, 24 h, 48 h and 72 h in the PG group (2.56±0.96, 2.47±0.96, 1.93±0.99, 0.98±1.24) were better than those of the DG group (4.00±1.60, 3.62±1.48, 3.36±1.55, 2.47±1.78,P=0.000, P=0.000, P=0.000, P=0.002). And the same results were found in the postoperative coughing VAS assessment. The mostly reported pain location was the chest drainage, incision site and chest wall in turn. Postoperative pain properties, in turn, were swelling, stabbing pain and numbness. Conclusion Postoperative pain after VATS lobectomy may be adequately controlled using parecoxib sodium. The low pain scores and decreased adverse effects are achieved.