The popularization and development of big data and cloud computing in e-commerce still face a series of problems, among which the most prominent one is security. How to establish an effective risk assessment system in the cloud computing environment is the primary concern of e-commerce enterprises. This article mainly discusses the network security of e-commerce based on big data in cloud computing environment. Because the servers of the cloud computing platform are deployed on a global scale, all the above nine processes can be carried out in real time, thereby improving the operational efficiency of the enterprise. Moreover, in large-scale e-commerce applications, according to probability statistics, the distribution of all these process steps must be uniformly distributed. Cloud computing is the commercial realization of computing resources, which is essentially a producer-consumer model. Cloud computing can balance the load to the greatest extent and solve various inconsistencies that may exist in the process of data processing. Balanced conflict greatly improved the solution. The speed, at which the case process runs, maximizes the potential of cloud computing on a commercial level. This article makes an effective investigation of information assets in various aspects. In this article, the comprehensive risk value of the system was calculated as 4.4. According to the risk level, this article sets up the electronic commerce system’s physical security and access and data backup control vulnerability to resolve problems; another big data reflect is also not allowed to ignore. In view of these problems, this article proposes corresponding improvement strategies responsibility allocation.