To address global climate governance and carbon reduction challenges, the Center for Energy and Environmental Policy Research (CEEP-BIT) at Beijing Institute of Technology developed the Carbon Reduction Technology System Model (C3IAM/NET) based on the “time–space–efficiency–benefit” coordination theory. The model covers key industries such as power, steel, cement, chemicals, non-ferrous metals, construction, and transportation, adopting a bottom-up technological perspective to simulate energy and material flows in production processes and optimize low-carbon technology pathways. Through demand forecasting, technology optimization, and policy constraint modules, C3IAM/NET quantifies emission reduction potential and costs under cost-minimization objectives, supporting industry-specific decarbonization. Additionally, the model establishes a multi-regional collaborative emission reduction optimization framework (Mr. COEP), which coordinates regional heterogeneity in economy, energy structure, and technological maturity to synchronize national carbon peaking and neutrality timelines while maximizing overall benefits. By integrating dynamic programming and multidimensional constraints, C3IAM/NET provides scientific tools for technological upgrades, fuel substitution, and policy design, facilitating China’s sustainable transition under dual-carbon goals.