The invention discloses a method and system for identification of dynamic change of traditional Chinese medicine constitutions. The method comprises the steps that constitution identification data arecollected based on a scaling identification method and traditional four diagnostic methods, and the constitution identification data comprise the multiple traditional Chinese medicine constitutions and constitution impact factors corresponding to the traditional Chinese medicine constitutions; a knowledge database is constructed; the knowledge database is analyzed through a gray relative analysismethod, and the multiple traditional Chinese medicine constitutions and the key constitution impact factors corresponding to the traditional Chinese medicine constitutions are gained; and knowledge mapping is constructed based on the multiple traditional Chinese medicine constitutions and the key constitution impact factors corresponding to the traditional Chinese medicine constitutions. According to the method and system, the gray relative analysis algorithm and the knowledge mapping technology are applied to show the key constitution impact factors impacting the traditional Chinese medicineconstitutions more objectively, and the key constitution impact factors impacting the traditional Chinese medicine constitutions are scientifically quantized; and the system automatically outputs thekey impact factors of the traditional Chinese medicine constitution types through corresponding programming setting, the key impact factors are used for assisting a doctor for constitution diagnosis,by adopting the system, using is convenient, and the efficiency is high.