Abstract: Objectives: High-definition (HD) maps are essential infrastructure for autonomous driving, characterized by high collection costs, significant economic value, and containing a substantial amount of sensitive geographic and road information. Ensuring their security and privacy protection has become an urgent priority. As the foundation of data security, encryption technology can provide the technical support necessary for the secure storage and transmission of HD maps. Aiming at the security protection problem of high-precision maps in storage and transmission, a dynamic encryption algorithm for high-definition maps in OpenDrive format was proposed based on the data characteristics of HD maps and DNA dynamic coding. Methods: The algorithm consists of two main components: scrambling and diffusion. During the scrambling process, a random sequence is first generated using the SHA-512 hash algorithm in conjunction with a two-dimensional chaotic system. Next, the parameterized cubic curves representing elevation, superelevation, and lanes in the HD map are mapped to corresponding base combinations using this random sequence. The parameters within the curve are then scrambled according to the principle of base complementarity. In the diffusion operation, the DNA bases are first encoded, and a stable index relationship between each curve and the encoding scheme is established through a random sequence. Secondly, the parameters of the curve are base-encoded in binary. Then, the DNA addition operation is performed according to the index encoding scheme. Finally, the operation result is converted into decimal to obtain the ciphertext data. Results: The experiment demonstrated that the algorithm provides high security, with a large key space and strong key sensitivity. The encryption algorithm demonstrated effective performance, enabling selective encryption and decryption. Additionally, in the event of cropping attacks on the HD map, the unaffected portions of the data can still be successfully decrypted. Conclusions: The algorithm is suitable for the secure storage and transmission of highdefinition maps in intelligent connected vehicles. Its selective encryption and decryption capabilities make it adaptable to various application scenarios, offering strong practicality.