Abstract: In the general trend of the port low-carbon transition, the loan for the port logistics financial inventory pledge has been developing rapidly in practice and it is very urgent how to integrate the low-carbon port constraint factors in the decision making of the port logistics inventory pledge loans so as to promote indirectly the transformation and upgrading of the port. In this study, the port pledge loan interest rate decision-making theory in the low-carbon transition was deeply studied, based on the proposed default option-adjusted spreads, low-carbon adjustment spreads and pledge risk control principles, and the strong liquidity inventories of low-carbon port logistics pledge loan interest rate decision model was established, and derive the pledge loan optimal rate under the scenario of default option-adjusted spreads and low-carbon adjustment spreads. At the same time, the pledge price, market interest rate and carbon emission control cost and various parameters which affect the pledge loan optimal rate formula are derived. Finally, the actual data of a certain port was used to perform sensitivity analysis calculations to verify the model's feasibility and usability.

Key words: pledge loan interest rate, low-carbon port, default option-adjusted spreads, carbon-emission-adjusted spreads, pledge rate