Image-guided local thermal ablation plays an increasingly important role in the treatment of live cancer, and the safety of this therapy deserves some attention. The major complications of thermal ablation include bleeding, biliary complications, gastrointestinal perforation, infection, thoracic and diaphragmatic complications, etc. Any major complication may significantly affect the quality of life after treatment and even lead to death. Therefore, identifying the cause of each complication and mastering preventive measures and treatment methods are crucial to reducing major complications of thermal ablation.