This book CCIS 2774 constitutes the refereed proceedings of the 40th CCF National Conference of Computer Applications, CCF NCCA 2025, held in Beijing, China, during August 7-9, 2025.

The 43 full papers presented in this book were carefully selected and reviewed from 269 submissions. These papers have been organized in the following topical sections:

Artificial Intelligence and Applications

Cyberspace Security Technology

Data Science and Big Data Technology

Frontier Technology Applications