<p>The rapid development of quantum computing poses a serious threat to traditional encryption techniques, especially in the field of image security, where traditional encryption schemes are difficult to resist quantum attacks. Therefore, research on quantum image encryption is crucial. In the research of quantum image encryption, the high randomness and high security of quantum keys have become the core elements to ensure system robustness. Therefore, in order to provide high-quality quantum keys, this study is inspired by low-dimensional quantum walk and proposes two quantum key generation schemes with high randomness: one is to construct a high-dimensional quantum walk paradigm using the physical properties of quantum walk; the second is to enhance the randomness of the basic quantum key by introducing an entropy-increasing circuit. On this basis, in order to verify the randomness and security of the key, a quantum walk-based scrambling algorithm and a shift-overlap XOR diffusion algorithm were designed, and corresponding quantum circuit implementations were provided. Finally, the proposed method was validated through security experiments. The experimental results show that the average entropy of the encrypted information is 7.9991, which is close to the ideal value, indicating that the key has good randomness. The robustness test results show that the ciphertext can effectively resist salt, pepper, and noise attacks. Meanwhile, the analysis of plaintext sensitivity shows that the NPCR value is 99.5431 and the UACI value is 33.5228, both of which meet the requirements of secure encryption systems.</p>