Sports has become a part of people's healthy life, and sports injuries are increasing at the same time. Injuries are quite common especially in sports and military training. The mild sprain of ankle joint will affect the sports level , while severe sprain will lead to repeatedly sore pain of the ankle joint, result in chronic ankle instability, and then impact the athletes or soldiers' career. The progress in recent years in ankle sprain principles, probability and it's prevention were introduced in this paper.
