Fault injection attacks can compromise cryptographic operations with out the necessity of physical alteration, thereby potentially disclosing private keys, which poses a grave threat to the security of elliptic curve digital signature algorithms. This letter presents an efficient and prac tical lattice-based fault injection attack on the SM2 digital signature algorithm (SM2-DSA), along with the corresponding defense strategy. The proposed attack method significantly reduces the moment precision requirements compared to existing lattice-based fault attacks, while also demonstrating computational advantages over other fault attacks. From the defensive perspective, the proposed strategy effectively defend against the lattice-based fault injection attacks while minimizing both time and spatial overheads. Specifically, our countermeasure incurs only a 0.8% time overhead and the area overhead for secure design does not exceed 1%. Our research provides valuable insights for evaluating the security of hardware implementations of SM2-DSA.