With the continuous development of big data and artificial intelligence technology, the accounting and auditing industry is also experiencing unprecedented changes. The purpose of this study is to explore the application of big data in accounting audit and its impact on audit quality and efficiency. Through in-depth analysis of existing literature and empirical research, the study found that big data can not only improve the accuracy and timeliness of audits, but also promote the professional development of auditors and the sustainable development of the industry. At the same time, this study also focuses on the specific application of emerging technologies such as artificial intelligence and machine learning in auditing, and analyzes the challenges and ethical issues that these technologies may bring. Finally, the study proposes a series of implementation strategies and best practices to guide audit practices, education and training, and policy development. Overall, this study provides a strong theoretical support and practical guidance for the innovation and development of the audit industry, and helps to promote the accounting audit into a smarter and more efficient new era.