Abstract: As the world's largest tobacco consumer, China faces increasingly severe health and socioeconomic burdens caused by secondhand smoke exposure. This paper examines the necessity of national smoke-free legislation in China, based on evidence that comprehensive smoke-free laws can significantly reduce secondhand smoke exposure rates and mitigate health risks such as cardiovascular diseases and lung cancer, thereby alleviating public health burdens. By reviewing international progress and outcomes in smoke-free environment legislation, and analyzing China's current tobacco control policy advancements, regional legislative disparities, and enforcement challenges, this study aims to facilitate the achievement of the tobacco control objective outlined in the "Healthy China 2030" initiative.