With the rapid growth of information resources and increasing individual demands of farmers, the problem of how to organize complicated information effectively in agricultural risk management and provide efficient information services has become more and more important. Research on architecture of agricultural risk-oriented domain ontology-based information integrated service is studied. The ontology molecule theory, which is a new theory in ontology field, is introduced and utilized in this paper. Based on the ontology molecule theory, the paper builds a frame of the agricultural risk ontology and proposes the architecture and implementation of the agricultural risk-oriented information integrated service. At the end, this article points out that the future research is to establish an ontology-based information service system for the agricultural risk management, in order to better predict the agricultural risk and reduce its effect to farmers.