China is in a period of multiple environmental risks,and preventing environmental risks is now a top priority for us. Facing with a serious environmental risk situations,we should use comprehensive methods,of which the legal mean is indispensable,to guard against the environmental risks. In China's existing environmental legal system,the law related to environmental risk prevention is not few,but the law that clearly defined the environmental risks is rare. In this paper,we put forward the proposal of setting up the Environmental Risk Prevention Law,aiming to establish the precautionary principle and clarify the duty of environment risk monitoring and warning institutions,all of which are supported by specific methods in the improvement of environmental risk control system， environmental risk precaution system,environmental risk information disclosure system and environmental risk assessment system the construction of environmental risk source survey system.