As the advanced productivity of the traditional productivity butterfly, the new quality productivity is the core driving force to promote the transformation and upgrading of the whole chain of key industries, and it is also the important material and technological basis for realizing the Chinese modernization. This paper constructs a new quality productivity evaluation index system by selecting 20 specific indicators from the three dimensions of scientific and technological innovation, industrial upgrading and development conditions of financial new quality productivity, and measures the development level of China’s financial new quality productivity from 2008 to 2022. On this basis, the entropy weight Topsis method, Dagum’s Gini coefficient and β-convergence were further applied to analyze the regional differences in the development of financial new quality productivity and the convergence of the development level. Based on this, the panel data of Chinese provinces are used as the research samples, and various econometric models are constructed to empirically investigate the relationship between the new financial productivity and the modernization of the rural industrial chain supply chain as well as the mechanism of the role of the new financial productivity. It is found that the development level of financial new quality productivity in China and the four major regions is on an upward trend, and the differences between and within groups in China and the four major regions are on a decreasing trend, and the changes in the overall differences mainly depend on the inter-regional differences. Meanwhile, the development level of financial new quality productivity in China and the four major regions is characterized by β-convergence, but there are differences in the speed of convergence. The empirical test concluded that financial new quality productivity has a positive promotion effect on the modernization of the rural industrial chain supply chain.