With the advent of quantum computing, blockchain systems based on elliptic curve cryptography and hash functions face serious security threats from Shor’s and Grover’s algorithms. To address this, we propose a quantum-resistant blockchain transaction model using the post-quantum signature scheme CRYSTALS-DILITHIUM. The traditional elliptic curve digital signature in the UTXO model is replaced with DILITHIUM, and a simulated blockchain system is built to evaluate performance. Experimental results are analyzed to compare efficiency and scalability. Given the large size of post-quantum signatures and public keys, a scaling solution is introduced by separating transaction and verification data, storing the latter in extended blocks to enhance transaction throughput. To address wallet security in the event of secret key loss, a multi-wallet mechanism is also designed to maintain security under quantum attacks. The overall solution is tested in a simulation environment to verify its practicality and performance under post-quantum conditions.