In the global wave of digital economy, digital transformation has become a core driving force for reshaping national industrial patterns and enhancing global competitiveness. Taking China and Belarus as case studies, this paper constructs a three-dimensional co-evolutionary framework of economy, technology, and security (ETS) to explore the complex interaction mechanisms of economic efficiency improvement, innovation-driven development, and security risk prevention during the transformation process. The research reveals that China has achieved comprehensive restructuring through its scale advantages and systematic strategies, while Belarus has developed specialized IT service industries by leveraging professional breakthroughs and geostrategic bridging. The practices of both countries demonstrate that successful digital transformation requires dynamic balance and coordinated development of ETS, particularly under the context of the "Digital Silk Road," where international cooperation, standard alignment, and institutional innovation are key to achieving a sustainable and secure digital future.