Science identity plays a critical role in fostering adolescents’scientific literacy and cultivating national scientific talent. Science identity，derived from the psychological concept of“identity，”refers to an individual’s possession of scientific capabilities，ability to work like a scientist，self-recognition as a“science person，”and acknowledgment by others as such. Science identity is conceptualized through four frameworks：the single-dimensional“recognition”framework，the two-dimensional“self-social”framework，the three-dimensional“recognition-competence-performance”framework，and the four-dimensional“recognition-competence-performance-interest”framework. As an ontological marker of adolescents’scientific literacy development，science identity functions as both a means of identifying and expressing scientific literacy ontologically and a framework for evaluating it. The practical pathway to enhancing adolescents’scientific literacy through the lens of science identity can be summarized in three steps. First，adolescents establish science identity standards during scientific learning to cultivate an ontological awareness of scientific literacy. Second，they“input”science identity through social interactions，thereby activating this ontological awareness. Third，they compare their science identity during scientific practice to validate this awareness，ultimately“outputting”a subjective understanding of scientific literacy.