Objective The aim is to establish a new analytical method of relationship between injury and disease in forensic clinical identification of post-traumatic tooth loss.Methods 25 cases of post-traumatic tooth loss were collected.The main factors that affect the judgment of the relationship between injury and disease were selected and weighted.And the method was verified by 18 case from CNKI.Results A total of five indicators were selected and weighted,including the missing mode,the root number of missing teeth,the fracture of alveolar bone,the damage of soft tissue and the degree of periodontal disease.The interval of the score is used to determine the results of relationship between injury and disease.Conclusion The method is accuracy and acceptable,and can be used to evaluate the relationship between injury and disease of post-traumatic tooth loss.