To identify the expression of miR-520a-3p and AKT1 in non-small cell lung cancer cells (NSCLC) and the mechanism in inhibiting cell invasion and metastasis by targeting NF-kappaB signaling pathway. Bioinformatics analysis and dual luciferase reporter gene assay were used to predict and verify the targeting relationship between miR-520a-3p and AKT1. EdU assay was used to detect the proliferation of NSCLC cells. Flow cytometry detected the apoptosis of NSCLC cells. Transwell assay tested the invasion ability of NSCLC cells. qRT-PCR measured the expression of miR-520a-3p and AKT1 mRNA in NSCLC cells; while western blotting was adopted to detect the protein expressions of AKT1, Ki67, CyclinD1, Bax, Bcl-2, MMP-2, MMP-9, NF-kB p65, IkBs kinase (IKK), NF-kB inducing kinase (NIK). Bioinformatics analysis suggested that miR-520a-3p could target AKT1. miR-520a-3p could regulate the expression of AKT1 negatively. Compared to mimic-NC group, miR-520a-3p mimic group had increased expressions of miR-520a-3p and Bax, while decreased expressions of AKT1, Ki67, CyclinD1, Bcl-2, MMP-2, MMP-9, NF-kB p65, IKK and NIK, reduced cell proliferation, invasion, and increased cell apoptosis rate (all P < 0.05). Compared to inhibitor NC group, miR-520a-3p inhibitor group had decreased expressions of miR-520a-3p and Bax, but increased expressions of AKT1, Ki67, CyclinD1, Bcl-2, MMP-2, MMP-9, NF-kB p65, IKK and NIK, promoted cell proliferation, invasion, and suppressed cell apoptosis rate (all P < 0.05). Overexpression of miR-520a-3p can target and downregulate the expression of AKT1 to inhibit the invasion and metastasis of NSCLC via suppressing the activation of NF-kappaB signaling pathway.