With the deep development of big data and artificial intelligence technologies, corpus research has garnered increasing attention and recognition. Initially, corpora were collections of speech materials aimed at linguistic research; now, they serve as deeply annotated knowledge resources supporting knowledge discovery and extraction. One of the most popular research areas is the integration of corpora with teaching. Studies have found that corpora, as an empirical research tool, provide rich authentic language materials for English writing instruction. This exposure helps students encounter genuine language use, improving the accuracy and authenticity of their writing. We recognize the multifaceted advantages of applying corpora in English writing instruction. These benefits include aiding students in identifying and correcting writing errors, enhancing language awareness, enriching writing resources, and fostering innovation in teaching models. The study categorizes the application of corpora into two main types: indirect and direct use. Indirect use of corpora reveals common issues in English writing and provides theoretical basis and practical guidance for improving teaching resources and methods. Direct use of corpora focuses more on practical operations, showing more significant effects in writing instruction by correcting specific writing errors, and innovating teaching models and methods, thereby directly promoting students' writing skills. Although research on corpus-assisted English writing abilities has yielded considerable results, there is still room for improvement. It is suggested that research outcomes should be closely integrated with frontline teaching practices and expanded research samples. Teachers need to incorporate corpus tools and methods into everyday teaching to achieve mutual promotion of research and teaching. Moreover, educational departments and schools should provide professional training to enhance teachers' corpus knowledge and application skills. Additionally, students' attitudes towards and proficiency in using corpora should be emphasized, encouraging them to actively use corpus resources for exploratory learning and self-correction. Future research could further explore the retrieval efficiency of corpora and the intelligence level of their teaching applications, combining interdisciplinary research to comprehensively understand and explore the overall role of corpora in English writing instruction, thereby better advancing the role of corpora in improving English writing skills.