On the basis of fundamental ethical principles and requirements, combining the practice of ethical management and according to the characteristics and requirements of the prospective cohort study of natural populations, this paper probes into the many key points of ethical design, including the use of existing data, the choice of exposures, the protection of special population subjects and the renewal of informed consent, and the selection of prospective cohort study of natural populations, to provide the beneficial reference to maximize the guarantee of the safety and rights and interests of the subjects.