Abstract: Based on the green patent data of listed enterprises from 2010-2021,a flexible double difference model (ESA-DID)is constructed to empirically analyze the dynamic effects of green credit policy on green innovation of heavily polluting enterprises based on the release of the Green Credit Guidelines in 2012 as a natural experiment.The study finds that:firstly,the dynamic effects of green credit policy on total innovation,substantial innovation and strategic innovation of heavily polluting enterprises are short-term suppression and long-term promotion,and the short-term suppression effect first increases and then decreases.Secondly,the effect on substantial innovation has a lagging effect,and the promotion effect on strategic innovation is stronger than that on substantial innovation in the long run.Finally,from the perspective of the mechanism of action,green credit policy effectively promotes both aggregate and substantial green innovation through credit constraints.