A Guide to College English Teaching (the latest edition by China's Ministry of Education in 2017) puts forward higher requirements than ever before for improving the English writing ability of college students in China. At the same time, it also points out that "every university should make full use of information technology and actively create a pluralistic teaching and learning environment. Teachers are encouraged to build and use micro-classes to take advantage of qualified online education resources to transform and expand teaching contents, and to implement blended teaching models such as flipping classes based on courses taught in classrooms and online." At present, college English teaching in China, especially in writing teaching, is usually not systematic. Blended teaching of English writing through guidance, supervision and evaluation before, during and after class can solve this problem to a great extent and achieve relatively good teaching effect.