Agricultural digitalization effectively empowers the construction of the whole agricultural industry chain，which is the key to advancing agricultural and rural modernization. Based on panel data of 30 provinces in China from 2012 to 2021，this study employs the Agricultural and Rural Big Data Pilot Policy as a quasi-natural experiment and adopts a difference-in-differences （DID） model to examine the impact and mechanisms of agricultural digitization on the construction of the whole agricultural industry chain.The results show that agricultural digitization significantly promotes the construction of the whole agricultural industry chain，and this effect is more pronounced in non-main grain-producing areas， regions with strong fiscal support，and areas with high levels of industrial structure upgrading.Further analysis reveals that agricultural digitalization effectively empowers the construction of the whole agricultural industry chain through three channels：promoting agricultural technological innovation， improving rural human capital， and enhancing farmers’consumption levels. Based on these findings，feasible policy recommendations are proposed in terms of formulating differentiated policies，continuously promoting technological innovation， and strengthening rural human capital and talent development.