How to achieve the innovation in producer services in China is one concern of agro-industry policies and academic circles. This paper sorts out the evolution of contract agriculture, and shows that the excessive profit-driven feature of traditional agricultural companies leads to low efficiency of agricultural supply chains and seriously restricts the sustainable development of "corporation + farmer" mode. This paper uses social function of supporting vulnerable groups and sustainable business operation possessed by social enterprises to introduce relational and structural embeddedness mechanisms, and explores business mode innovation of traditional make-to-order agriculture by agricultural social enterprises. And it employs the data of village survey to verify this view and comes to the following conclusions:firstly, the participation of agricultural social enterprises not only motivates farmers to be engaged in agricultural production, but also is very helpful to the improvement of farmer performance; secondly, high-level relational and structural embeddedness may bind the interests of farmers to that of social enterprises, and may greatly promote the sustainable agricultural development in China; thirdly, there is a need to explore a new business model to diversify the agro-industry since traditional make-to-order agriculture has difficulty in adapting to the development of modern agro-industry in new situation.