Considering the low degree of abstraction of traditional shape grammar in national pattern reuse design, this paper proposes a method based on the combination of improved shape grammar and an optimization algorithm to reuse national patterns design. As an application example, we carried out research on the batik pattern elements of the Miao nationality in the “Intangible Cultural Heritage of Guizhou Province” system. Firstly, an improved shape grammar based on synthetic predicate grammar coding is developed to represent the transformation process of design pattern reuse in batik patterns. Then, the number of patterns arranged in a specific position is taken as the optimization variable; the particle swarm optimization algorithm is used to optimize the variables, so as to obtain the optimized predicate shape grammar parameters; and the pattern is reused according to the parameters. A batik design pattern reuse system is also constructed to realize rapid design. The results show that the proposed method can enrich the reuse results of batik pattern elements and realize the rapid design of complex batik patterns.