English writing obviously weighs much in College English teaching.Efficiently improving students’ writing is one of the focal points.Cognitive-functional approach organically combines the cognitive approach and the functional approach together,emphasizing the perception of language norms,communication and the output of standardized language.With the theoretical direction of cognitive-functional approacht,his paper puts the teaching of College English writing into the datform of web log,explores the building and peculiarities of the writing teaching model of cognitive-functional approach based on blog,analyzes the study of students in the process of "experiencing-perception-commenting-supervising-feedback-cooperation-perfect",and finally points out what should be solved in practicing this teaching model.