With the wide application of Internet technology, the application scope of big data technology in all walks of life is expanding. The widespread use of the Internet has led to the generation and accumulation of massive data, which is not only a valuable information resource, but also a challenge to information security. In the current big data environment, computer information security faces many key technologies and challenges, such as data privacy protection, network attack prevention, identity authentication, and so on. To address these challenges, this article will focus on exploring the application of big data technology in the field of computer information security. In the big data environment, data storage, transmission, and processing face more complex security issues. At the same time, the application of big data technology also provides new possibilities for information security, such as security event detection and response systems based on big data analysis and network intrusion detection systems based on behavior analysis. Through in-depth analysis and effective protection strategies in this article, the aim is to provide practical references for related research and promote the continuous development and innovation in the field of computer information security. In the research, we will further explore the integration of big data technology with emerging technologies such as artificial intelligence and blockchain to address the increasingly complex challenges in the field of information security and achieve a positive interaction between information security and technological innovation.