Abstract The security core of blockchain technology relies on digital signature schemes. However, existing schemes face numerous challenges when applied on a large scale, such as complex key management, reliance on certificate infrastructure, potential key escrow risks, and lack of resistance to quantum computing capabilities. To address these issues, this paper proposes a novel enhanced certificateless identity-based digital signature scheme. This scheme ingeniously integrates certificateless cryptosystem and lattice cryptography, aiming to simultaneously achieve identity-friendly public key management, effectively mitigate the key escrow problem, and lay theoretical foundation for post-quantum security. This paper first presents the formal definition and detailed construction of the scheme. Then, under the random oracle model, the security of its existence being unforgeable is reduced to the computational difficulty of the short integer solution problem on the lattice. The performance evaluation of the system shows that, compared with the traditional scheme based on bilinear pairing, this scheme significantly improves security while maintaining reasonable computational overhead. Experimental results show that at the 128-bit security level, the signing time is 4.8 ms and the verification time is 2.1 ms. Finally, this paper elaborates in detail on the application model of this scheme in secure blockchain transactions, demonstrates how it simplifies the transaction process by using human-readable identity identifiers, and through its anti-quantum and decentralized trust characteristics, provides a powerful cryptographic primitive for building the next generation of secure, efficient and user-friendly blockchain systems.