Long non-coding RNA ITGB1-DT is involved in the regulation of cancer growth and metastasis. However, the roles of ITGB1-DT in non-small cell lung cancer (NSCLC) progression and sensitivity to cisplatin has not been elucidated. ITGB1-DT expression in NSCLC tissues, and the relationship between ITGB1-DT expression with NSCLC diagnosis, prognosis, clinicopathological features, and immune cell infiltration were investigated in The Cancer Gene Atlas (TCGA) database. The roles and mechanisms of ITGB1-DT in cell growth, migration, and drug sensitivity of NSCLC cells were explored in the cell model. The prognostic nomograms of ITGB1-DT-related genes were evaluated using bioinformatics. ITGB1-DT was overexpressed in NSCLC. Elevated ITGB1-DT expression was related to the late T stage, N stage, M stage, short overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) of NSCLC patients. ITGB1-DT was the independent risk factors for poor prognosis, and had diagnostic value for NSCLC patients. Interfering with the ITGB1-DT expression can inhibit the proliferation, migration, and invasion of A549, H1299, and drug-resistant A549/DDP, possibly due to the inhibition of p38 MAPK and ERK phosphorylation levels. ITGB1-DT expression was correlated with the levels of NSCLC immune infiltration cells, such as the TReg, Th, and NK cells. ITGB1-DT-related gene nomograms were associated with the prognosis, and were expected to evaluate the prognosis of NSCLC patients. In conclusion, inhibition of ITGB1-DT expression delayed the growth and metastasis of NSCLC using the MAPK/ERK signaling mechanism and enhanced the sensitivity of NSCLC to cisplatin drugs. These results indicate that ITGB1-DT might be a biomarker for evaluating the diagnosis and prognosis of NSCLC patients.