This article aims to enhance the effectiveness of modern accounting audits, conduct in-depth analysis of cloud accounting environments using cloud computing technology, and study big data audit techniques under the guidance of COBIT standards. The research uses probabilistic algorithms to analyze the parallel solution of data. Based on the COBIT5.0 dimension of contributing factors, the implementation framework of the “Internet plus + Audit” model based on cloud accounting is constructed from seven specific factors: principles and policies, cultural atmosphere, personnel requirements, organizational structure, information resources, infrastructure and process design. By combining quantitative and qualitative analysis methods, threats from enterprises and cloud providers are evaluated, and vulnerability analysis is conducted. Through simulation analysis, the effectiveness of the big data audit method based on COBIT standards proposed in this article in the cloud accounting environment has been verified. This method can significantly improve the effectiveness of accounting and auditing, achieving efficient data processing and rapid generation of audit decisions. For auditing units, especially small and medium-sized ones, this method helps to break down technical barriers and promote service optimization and innovation. At the same time, the integration and collaboration of cloud resources will promote the transformation of audit mode to joint audit mode, achieve the integration of high-quality resources, and improve the independence and efficiency of auditing.