Abstract: Bank credit serves as the primary source of funding supporting corporate innovation, and the credit maturity structure exerts a significant influence on corporate innovation. This study utilizes data from listed “Specialized, Refined, Distinctive, and Innovative” enterprises in China spanning 2013 to 2023 to empirically examine the impact of the proportion of short-term credit on corporate innovation and its underlying mechanisms. The findings reveal that an increase in the proportion of short-term credit suppresses the innovation level of listed “Specialized, Refined, Distinctive, and Innovative” enterprises, a conclusion that remains robust after endogeneity and robustness tests, including the double machine learning method. Heterogeneity analysis indicates that the inhibitory effect of an increase in the proportion of short-term credit on innovation is more pronounced for listed “Specialized, Refined, Distinctive, and Innovative” enterprises in their growth stage, whereas for nationally designated “Specialized, Refined, Distinctive, and Innovative ‘Little Giant’” enterprises, an increase in the proportion of short-term credit has no significant impact on corporate innovation. Mechanism tests further show that a higher proportion of short-term credit primarily suppresses corporate innovation by exacerbating maturity mismatch in innovative firms.