Achieving simultaneously high efficiency and thermal stability in perovskite quantum dot light-emitting diodes (PeLEDs) requires fundamentally rethinking surface ligand design. Conventional OAm-OA ligands inadequately passivate halide vacancies, causing defect-induced exciton quenching and low efficiency. Beyond this limitation, we reveal for the first time that thermal field triggers ligand entanglement at the atomic scale, which destabilizes the N─H passivation network, induces ligand desorpti