In the current Internet of Things （IoT） environment， Decentralized IDentifier （DID） management methods face multiple challenges， including linkage attacks， privacy leakage， and regulatory conflicts. There is an urgent need for a new scheme that can protect user privacy while meeting regulatory requirements. A DID scheme was proposed to address these issues. In the scheme， an identity system combining a main identifier and multiple pseudonymous identifiers was adopted， a dual-credential model was designed， thereby integrating plaintext credentials and encrypted credentials， and commitment and Zero-Knowledge Proof （ZKP） technologies were utilized to ensure the security of sensitive attributes and identity data. Furthermore， pseudonym mechanisms were applied to achieve unlinkability of identity information and defend against Sybil attacks effectively. Experimental results show that compared to the schemes such as WeIdentity， the proposed scheme reduces the credential generation time and proof generation time by 23% and 19%， respectively， demonstrating significant advantages in performance. It can be seen that the proposed DID scheme enhances user identity privacy protection， reduces identity leakage risks， and balances privacy protection with regulatory requirements， providing a solution for DID management in IoT environment.