By using selfidentity development theory of Erik Erikson, by analyzing adverse factors faced by selfidentity development of the floating teenagers of Wuhan City of Hubei Province, e.g. the floating teenagers have contradictions in their selfconsciousness, have deviation in self and social cognition and have problems in family education method and parentchild relation, the schools for holding the children of migrant workers are short of teachers, have backward teaching condition and are deficient in communication with the peer children whose parents are urban inhabitants, the communities for the floating teenagers to gather have inadequate facilities and poor sanitary condition and social mainstream factors have negative influence on the floating teenagers, this paper discusses the strategy for school social work to involve in selfidentity of the floating teenagers to optimize the social environment for the floating teenagers to develop selfidentity and to boost selfidentity development of floating teenagers.