At present in the world, student learning outcomes are the focus of attention and important standard of higher education quality assessment, which profoundly influence and promote the paradigm change in the higher education field. Based on the analysis of the connotation of student learning outcomes, combined with case study, this paper reveals that learning outcomes are the key factor to promote the construction of first-class undergraduate education from "external motivation" to "internal power". Besides, this paper investigates the evolution of learning outcomes assessment and the main methods in America. Based on these investigations, this paper explains the mechanism of learning outcomes assessment on the improvement of talent training quality, and puts forward the practice approach.