In the recent years, worker's accidental syncope in the workplaces is frequently reported .These events often lead to death. Lack of awareness of occupational hazards and preventive procedures is major factor of risk. Without experience of emergent management and medical treatment are the main reasons of increasing death numbers. Here, most causes of syncope and methods of treatment well be introduced, especially the syncope caused by environmental intoxicants. And we hope this article could decrease the occupational hazards.