Abstract:According to the theorem of "Petty-Clarke", the highest stage of the development of regional industrial structure is in the form of "three, two, one" structure, namely the tertiary industry accounts for the largest proportion of GDP, followed by the secondary industry, and the primary industry is the last form of industrial structure. Data showed that the current industrial structure of Sangzhi County, the proportion of GDPaccounted for by the primary and secondary industries was not much different, and the tertiary industry was far ahead of the situation. The industrial structure presents obvious irrationality. Gray correlation analysis method was used to study the industrial structure and economic growth of Sangzhi County, the gray correlation between the three industries and GDP in Sangzhi County was analyzed, and finds that the tertiary industry plays the most obvious role in the economic growth of Sangzhi County, with the highest correlation, and the secondary industry has the lowest correlation with the economy, which is contrary to the form of "three, two, one" industrial structure.So,the development of the secondary industry is researched, based on which, relevant countermeasures are provided to promote the optimization of industrial structure and economic growth in Sangzhi County.