This study aims to solve the problem that the traditional online foreign language teaching system focuses on function development, ignoring system security, and has certain risks. An online foreign language education system is designed and developed based on the blockchain technology. First, the blockchain technology and key technologies of system design are described in detail. Second, the overall technical architecture of the system, functional modules, and business logic of each module are designed. Finally, the basic performance of the system is tested. The results show that the system can realize the user’s unrestricted office work and zero maintenance of the system. The separation of presentation logic and business logic facilitates the development and maintenance of the system. The system mainly includes six functional modules: user management, course management, course order, course study, course certificate, and credit authentication. These modules are guaranteed for daily teaching use. The event processing success rate of the six functional modules of the system is greater than 99%, and the processing success rate is relatively high. The central processing unit (CPU) usage and memory usage are both below 30%. The host throughput of the six major modules is greater than 100 times/s when processing services. The average response time on the terminal side is maintained below 0.5 s. The average response time of business-side processing is maintained below 0.4 s, which is in line with the standard. The event processing success rate of the constructed system is 10.75% higher than that of other systems, and the average response time, CPU usage, and memory usage are 53.38%, 51.49%, and 50% lower than other systems, respectively. Therefore, the proposed system has better performance. To sum up, the designed system has excellent throughput, event processing capability, response speed, and low CPU and memory occupancy when processing business and is suitable for promotion and use in foreign language online education in colleges and universities. The use of the proposed system can improve its overall teaching efficiency and quality. The purpose is to provide important technical support for the improvement of the security of the online foreign language teaching system.

In order to improve the online oral English teaching model, enhance its efficiency, and widen its utilization in university teaching, this study developed a rigorous oral English teaching model, constructed a comprehensive oral English evaluation model, and used PBL to guide the direction of oral English curriculum under the influence of big data-driven background. The use of online oral English teaching mode was realized to ensure that students can internalize knowledge in class. A complete teaching method was used to ensure that learners can master more knowledge in English class, promote the operation of online English learning in the network environment and create a safe learning environment for students, improve students’ oral English ability, improve oral teaching, and improve the integrity of oral teaching. The deepening of big data and online review teaching will be the requirements of the future teaching environment. Therefore, it was decided that only by making full use of all the advantages of information technology, combined with the background of education and teaching, can we explore the new education and training methods needed in the new semester.