In the new era of informatization, big data, and artificial intelligence, the education field has also set off a wave of informatization development of English education. Teaching writing has always been the focus and challenge of English teaching, but there are various problems in English writing teaching in China. Problems such as difficulty in writing, vague expression, unclear main points, simple sentence structure, low vocabulary, etc. How to effectively carry out English writing teaching courses is worthy of our serious consideration. Based on this, this article studies the reform of English writing teaching methods under the background of big data and artificial intelligence. Survey data shows that only 10.53% of teachers often combine online teaching resources with English writing teaching, 25% of teachers have hardly used them, and 64.47% of teachers occasionally use online teaching platform resources. This shows that the reform of English writing teaching methods needs to start from the aspect of education informatization.