Background Atezolizumab was effective and well tolerated in pretreated non-small-cell lung cancer (NSCLC). This meta-analysis assessed that the efficacy and safety of atezolizumab plus chemotherapy combination, compared to chemotherapy alone.Methods This meta-analysis included double-blind randomized controlled trials (RCTs) comparing atezolizumab plus chemotherapy combination with chemotherapy alone for NSCLC. The subgroups were the high expression of PD-L1（PD-L1-high）, the low expression of PD-L1 （PD-L1-low） and the negative expression of PD-L1 (PD-L1-negative). The hazard ratios (HRs) and odds ratios (ORs) with 95% confidence interval (CI) were calculated. The outcome parameters were overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and adverse events Grade 3-5（AEs G3-5）.Results A total of 6 articles were included in this meta-analysis. The results indicated that atezolizumab plus chemotherapy combination had better efficacy than chemotherapy alone for PFS (HR=0.64, 95% CI=0.60 to 0.70,P<0.001), PFS（PD-L1-high）(HR=0.41, 95% CI=0.34 to 0.51,P<0.001), PFS（PD-L1-low）(HR=0.63,95% CI 0.55 to 0.72,P<0.001) and PFS（PD-L1-negative）(HR=0.71, 95% CI=0.61 to 0.83,P<0.001). There were statistically significant improvements in terms of OS (HR = 0.79, 95% CI = 0.73 to 0.86,P<0.001) 、OS (PD-L1-high) (HR = 0.65, 95% CI = 0.48 to 0.88,P<0.01) and OS (PD-L1-negative) (HR = 0.84, 95% CI = 0.72 to 0.98,P<0.05). Significant benefits were observed in ORR (OR=1.81,95% CI=1.58 to 2.08, P<0.001), ORR（PD-L1-high）(OR=2.24,95% CI=1.24 to 4.06,P<0.01), ORR（PD-L1-low）(OR=1.51,95% CI=1.03 to 2.21,P<0.05) and ORR（PD-L1-negative）(OR=1.54,95% CI=1.05 to 2.27,P<0.05). Meanwhile, atezolizumab was well tolerated and the incidence of AEs G3-5 (OR = 1.32, 95% CI = 1.06 to 1.64,P=0.01). Conclusion The atezolizumab plus chemotherapy combination had excellent efficacy and great safety than chemotherapy alone for NSCLC. Furthermore, these benefits had nothing to do with the state of PD-L1 expression.