The audit business model under cloud computing environment is the trend of audit informationization in the future. On the basis of summarizing the evolution of audit business models under IT environment and explaining the concept of cloud audit and its research and application status at home and abroad from IT and audit views, this paper, with the audit business processes as the main line, analyzes the audit business model changes under cloud computing environment from three aspects: the combination of cloud services with audit, the implementation of audit business processes under cloud computing environment and the management of audit business process risk caused by the application of cloud computing. The research provides a theoretical basis for the mastery of cloud computing application of audit business process change, for better meeting the arrival of the age of the cloud audit.