Objective： To compare the outcomes of percutaneous laser disc decompression （PLDD） and PLDD with synchronous suction through syringe in the patients with herniated lumbar disc（HLD）. Methods： Forty-two patients with HLD on MRI and those who did not respond to conservative treatment for 6 weeks were randomly divided into group A and group B. In group A， the patients were treated with PLDD and those in group B with PLDD and synchronous suction through syringe. GaAIAS diode laser at 810 nm was used for the ablation in both groups. The treatment effect was evaluated by modified MacNab’s criteria on the 7th， 30th and 90th day. Results： Evaluated by modified MacNab’s criteria， the percentages of the excellent and good cases in total patients treated for group B and A were 80.95% and 57.14% on the 7th follow-up day， 85.71% and 66.67% on the 30th follow-up day， and 95.24% and 71.43% on the 90th follow-up day， respectively. Conclusion： Synchronous suction technique through syringe during PLDD improves the overall outcome in the treatment of herniated lumbar disc.