The decorative patterns on Gannan Hakka architecture reflect the history, culture, and social structure of the Hakka people. They are not only a spiritual treasure trove for the Hakka but also an extremely important material carrier of Gannan Hakka culture. To find more possibilities for value transformation in the context of digitalization, this article is based on the theory of cultural genes and deeply deconstructs the decorative patterns of Gannan Hakka architecture in terms of their explicit forms and implicit semantics, analyzing the types of patterns and their aesthetic characteristics. On this basis, it proposes a strategy for digital preservation, using computer technology to digitally collect, analyze, process, and preserve the patterns. Taking furniture design as a carrier, it employs shape grammar for multidimensional deduction, combining the needs and aesthetic preferences of the target users to construct the effects of furniture design, empowering the contemporary value transformation and application of Gannan Hakka architectural decorative patterns. This aims to enhance the aesthetic value and cultural connotations of furniture design and provide new approaches and methods for the digital preservation and innovative application of Gannan Hakka architectural decorative patterns.