Wheat and corn are the two most important grain crops in northern China, and at this stage, it is difficult to obtain professional information in the field of wheat and corn, the acquisition efficiency is low, and the accuracy is poor, which seriously restricts the production efficiency. The intelligent question answering system can efficiently and accurately automatically screen out professional information, to effectively solve the above problems. However, the existing intelligent question answering system for wheat and maize has too low matching accuracy and slow retrieval speed to be widely promoted. Therefore, an efficient and accurate two-stage matching algorithm is designed, which uses the BM25 algorithm to recall the candidate set, and then uses the BERT model to screen out the optimal solution based on the candidate set. Experimental results show that the algorithm has high retrieval accuracy and retrieval efficiency.