This paper explores the integration of large language models (LLMs) with China’s information technology application innovation (ITAI), highlighting transformative opportunities and challenges. It systematically analyses the impacts of LLMs across four domains: hardware, software, security, and ecosystem. For hardware, innovations such as advanced packaging and ISAs are proposed to address computational bottlenecks while enhancing energy efficiency. In software, lightweight middleware and hybrid transactional/analytical processing (HTAP) databases optimize resource scheduling and intelligent workloads. Security advancements include differential privacy frameworks for federated learning and full-lifecycle LLMs security assessments to mitigate adversarial threats. Ecosystem development relies on open-source collaboration. This paper emphasizes hardware—software codesign, privacy-preserving AI, and policy support to overcome technical fragmentation and regulatory challenges. By leveraging LLMs, ITAI can shift from functional substitution to intelligent leadership, establishing an autonomous, secure, and high-performance digital infrastructure to support China’s economic growth.