The global “dual carbon” goals have driven the green industry to become a core direction of economic transformation. As professional financial intermediaries, investment banks possess capabilities in green financial product design, Environmental, Social and Governance (ESG) risk assessment, and cross-market resource integration, playing an irreplaceable role in guiding capital flow to the green industrial chain and addressing financing obstacles. This study focuses on the innovative design of financial service models by investment banks for the green industrial chain, adopting literature analysis, data analysis (indicator comparison) as research methods. It first identifies the core pain points in the development of China’s green industrial chain finance, then designs three innovative service models, analyzes the challenges faced, and finally puts forward corresponding suggestions such as strengthening supervision and introducing relevant talents. The research is expected to provide practical references for investment banks to participate in green industrial chain finance and promote the high-quality development of the green economy.