The teaching process of English writing in the colleges can be carried out with more effective and innovative approaches in the network milieu, and the concept of collaborative learning can also become the basic teaching philosophy of English writing. The teaching conditions of English writing in some colleges and universities were analyzed. In general, the overall teaching conditions suffer from many deficiencies, which become the aspects for developing English writing teaching activities based on collaborative learning in the network milieu. Achieving the teaching outcomes of either collaborative English writing or English writing on the basis of collaborative learning is not easy. This paper will analyze the difficulty of college English writing teaching based on collaborative learning in the network milieu, and put forward specific suggestions for teaching.