Abstract: It first introduces the basic concept of big data and designs the big data mining model based on BP neural network, then realizes the parametric design of agricultural machinery product model based on Pro/Engineer,and realizes the agricultural machinery digital design system based on big data prediction model. The experimental results show that:from the experimental results, it can be seen that the system can quickly design agricultural machinery parts,greatly reduce the design cycle, reduce the number of product design modifications,which is of great significance for modern agricultural design and manufacturing.