Due to the increasing progress of IT and cloud computing technology, traditional teaching methods and instructional resources can no longer meet the needs of modern education. How to use network technology to optimize classroom teaching and improve the quality and effect of online education is a topic worthy of in-depth discussion. Based on the current situation of English online education, this paper analyzes the theoretical basis and application status of cloud computing and puts forward the optimization strategy of English online education under the network environment, combining with the theories of constructivism and collaborative learning and building an instructional resource sharing management system based on cloud computing. The system can provide a great quantity of high-quality instructional resources for English online education and further promote the optimization of English online education.