The important path for the high-quality development of the raw grain industry chain in the three provinces of Northeast China is for the new agricultural business entities introduce modern production factors into grain farmers through socialized services. Therefore, it is urgent to evaluate whether there are demonstration entities with high-quality development among these new agricultural business and service entities, and to make clear their high-quality development path to lead other new agricultural management and service entities in serving small grain farmers through socialized services. In this regard, an evaluation model of high-quality development of agricultural business and service entities was constructed, and was characterized by considering the introduction of socialized services of modern production factors, setting the target values of all indicators to fully realize high-quality development based on policy objectives, and counting them into weights. The evaluation results showed that socialized service companies in the basic and full-scale realization stages of high-quality development can be used as demonstration entities of high-quality development. They had the ability to lead other new agricultural business and service entities to apply modern production factors, and provide full-process services and digitally empower service contents. It is concluded that the key path for the above-mentioned demonstration socialized service companies, which could lead other new agricultural business and service entities and serve small grain farmers, is to establish a socialized service platform. This platform can introduce large language model and retrieval-augmented generation technology to intelligently generate socialized service schemes.