Abstract: Anonymous credentials are a privacy-preserving authentication method that verifies the holder's qualifications or attributes without revealing their identity, widely used in digital identity management, e-government, and digital banking. Anonymous credentials that comply with Chinese commercial cryptography standards have also garnered significant attention. However, existing anonymous credential schemes often depend on centralized issuing authorities, which not only restrict their applicability in decentralized networks but also introduce risks of system failures and privacy breaches caused by single points of failure. To address these issues, we propose a decentralized anonymous credential scheme based on SM2 commercial cryptography. The proposed scheme leverages blockchain networks to replace credential issuing authorities and employs zero-knowledge proofs to ensure the secure and reliable distribution of credentials. Additionally, the scheme enables users to selectively disclose attributes according to their needs, thereby effectively avoiding the excessive exposure of private information. We also explores the construction methods of zero-knowledge proofs that comply with Chinese commercial cryptography standards and proposes a set membership proof scheme based on SM2, providing a foundational tool for designing the SM2-based decentralized anonymous credential. Security analysis proves that the proposed SM2-based decentralized anonymous credential scheme satisfies both unforgeability and anonymity requirements. Performance experiments further show that the scheme maintains efficiency suitable for real-world deployment.