The PACIFIC study established the standard of care for immunotherapy consolidation after chemoradiotherapy (CRT) in patients with unresectable stage III non-small cell lung cancer (NSCLC). However, its benefit is limited in patients with driver gene mutations. The LAURA study established a new paradigm of targeted consolidation therapy after CRT for patients with EGFR mutations. Although retrospective data support the efficacy of ALK-TKIs, no randomized controlled trial (RCT) has clearly demonstrated the value of ALK-TKI maintenance therapy after CRT. This study adopts a multicenter, randomized, double-blind, placebo-controlled design aimed at evaluating the efficacy and safety of ensartinib in patients with ALK-positive unresectable stage III NSCLC.