Risk evaluation is fundamental to eliminate and prenent any kind of public emergencies ,while that for railway public emergencies is the foundation to guarantee railway sicurity.With the researches on the flow and methods of risk evaluation and the evaltation on railway public evtergencies during 2008 Beijing Olympic Games,the article puts forward measures and suggestions for risk control,providing reference for decision making by government departments,the Organizing Committee of Beijing Olympic Games,and the Security Coorduating Tean of Beijing Olympics as well as jproviding basis for solutions by the Security Control Center of Beijing Olympics and the relevant dipartments of railway sector.