Purpose: This study aims to analyze the interactions within the intellectual property pledge financing framework involving SMBMEs, banks, and third-party intermediaries, focusing on factors that promote sustainable cooperation. Methods: The research employs an evolutionary game model to simulate and analyze strategic interactions among the stakeholders, considering bounded rationality and asymmetric information. Results: Key findings include the positive correlation between SMBMEs’ reputation and timely repayment, the adverse effects of patent devaluation on cooperation, and the reasonable loan interest rates for facilitating GPPFG cooperation. The study also highlights the need for a transparent information platform and reasonable breach of contract compensation. Conclusions: The paper concludes that an efficient GPPFG mechanism is crucial for SMBMEs’ financial support and green transformation. It suggests that third-party intermediaries play a significant role in risk reduction and innovation facilitation. The study acknowledges limitations and calls for future research to explore technological innovations and improve intermediary service systems for SMBMEs’ sustainable development.