In the traditional structural design process, rural buildings require a lot of manual calculations and repeated modeling. However, due to the constraint of construction cost, they cannot be designed and checked professionally as urban types, and the safety and economy are difficult to meet the requirements. In this study, an intelligent design approach for structural design of rural light steel frame structure was proposed, including the intelligent modeling and optimization. Based on the automatic layer classification method (ALCM), optical character recognition technology (OCR) and adaptive block algorithm, BIM intelligent modeling method was proposed where layer recognition, the extraction of axis text data and wall contour were included, and generated structural models satisfied the requirements of engineering practice. Based on the proposed two-stage simulated annealing algorithm, the intelligent optimization method was proposed and verified by case histories. Results showed that the proposed intelligent design method was feasible. Compared with the traditional method, its time use could be shortened by more than 70%, and the material consumption and structural design parameters were similar.