This article analyzes the relationship between administrative rationality principle and health supervision and the theoretical and practical significance of bring administrative rationality principle to health supervision from the perspective of law ,then makes suggestions on using administrative discretion with administrative rationality principle. Administrative rationality principle has its particularity in the fields of health supervision which we should pay attention to: introducing the “unreasonable” review standard, making the administrative rationality principle exist in administrative legislation and selective discretion of administrative procedure, weighing and balancing the relationship between principles of administrative legitimacy and rationality, concerning the expansibility and variability of administrative rationality principle.