Objective To investigate the feasibility and clinical efficacy of Buck technique combined with Dynesys dynamic stabilization system for the treatment of lumbar spondylolysis. Methods Data of 21 cases of lumbar spondylolysis who received Buck technique combined with Dynesys dynamic stabilization system from January 2015 to June 2019 were analyzed retrospectively were analyzed retrospectively. There were 14 males and 7 females, aged 35.6±12.9 years (18-59 years). Diagnosis included: lumbar spondylolysis alone in 8 cases, and spondylolysis with grade I spondylolisthesis in 8 cases, and spondylolysis with discogenic low back pain in 5 cases. Clinical outcomes were evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI) at preoperative, postoperative 3 months and final follow-up. Three-dimensional computed tomographic (3-D CT) reconstruction was used to evaluate bony fusion at 12 months postoperatively. UCLA system was used to evaluate the degeneration of adjacent segments at preoperative and final follow-up. The complications were observed during follow-up. Results The patients were followed up for averagely 32.6±9.4 months. The VAS score and ODI scores were significantly improved at postoperative 3 months and final follow-up compared with those before surgery (P<0.01). The healing rate of pars was 95.2% (20/21) at 12 months postoperatively. Nonunion was observed in 1 case, but low back pain was significantly relieved. According to the UCLA grading scale, 12 cases were evaluated as grade I and 6 cases as grade II and 3 cases as grade III at the final follow-up, which was the same as preoperative grade and indicated no deterioration of adjacent segment degeneration. No major complications occurred in all patients. Conclusion The combination of Buck technique and Dynesys dynamic stabilization system is safe and effective in the treatment of lumbar spondylolysis with a high rate of isthmic fusion rate, especially in patients with grade I spondylolisthesis or discogenic low back pain.