With the rapid development of information technology, mobile communication, e-commerce and internet technology, human society has been brought into the era of big data. Big data contains huge social and economic value, it promotes the transformation of people's thinking mode, changes the train of thoughts and technologies for people to understand and study social and economic phenomena, and creates a new paradigm based on data management, data analysis and application. It has become an important driving force for the upgrading of existing industries and the birth of new industries. Data resources have become the basic strategic resources of a country, which is redefining the process and way of national strategic decision-making and social management, enterprise management decision-making, and individual decision-making. Big data will embed data analysis, data mining and artificial intelligence technology into the existing framework, thereby enriching the existing research framework and advancing research by opening the "black box" of economic processes. Big data also inevitably has a significant impact and reform on the audit industry of certified public accountants. Big data drives profound changes in the audit environment and audit object, etc. The organic integration of big data technology and audit theory and practice has been required for the development of the audit industry, which may become a turning point of modern audit. In this paper, the theory and practice research of this subject are analyzed from three dimensions, first of all, from the CPA audit profession development level, existing studies show that under the environment of big data, the basic theory of audit and the target may not change, but using big data in the audit has become inevitable, big data technology will be organic in audit practice, it is bound to drive the audit mode and audit subjects to change or put forward new requirements that conform to the characteristics of the times. The audit driven by big data will definitely affect the development path and direction of the audit industry in the future. Secondly, from the aspect of CPA audit mode, existing studies show that CPA audit will change "validation audit" type into "exploring audit" type, the evidence collection model of data auditing, method of data analysis as the core of the audit, deconstruction and reconstruction of the audit process, and synergy of several kinds of operating mode has become the direction of CPA audit mode change. Thirdly, from the audit subject level, existing studies show that the audit environment becomes more complex under the environment of big data, and the use of huge amounts of data greatly changes the thinking mode and operation mode of auditors, which will have a profound impact on the management and control of data risks, post structure, and staff quality of accounting firms. By sorting out the basic thread of thoughts of the overseas and domestic research, finally, the authors put forward the future research prospects from the macro and micro levels, in order to provide new ideas and methods for the development of audit work in the data era, so as to promote the development of the audit industry. At the same time, the research of this paper will also help the audit department to solve the problems existing in the audit practice, so as to adapt to the arrival of the data era, and play an important role in improving the audit function in national governance to some extent.