In order to explore the collaborative development of online procurement and inventory technology, this paper combines cloud computing technology to build online procurement and inventory management models, and builds a collaborative procurement computing experimental model with the help of a service system. Moreover, this paper clarifies the evolution problem of clustered supply chain network, and defines and constrains the model. In addition, this paper uses Agent technology to construct individual model and behavior model. Further, by complementing the advantages and disadvantages and mapping rules between Agent technology and Web service technology, the Agent model is mapped into a service model, which integrates the intelligence of Agent and the openness and cross-platform characteristics of Web services. Finally, this paper simulates the procurement and management model proposed in this paper through the simulation platform. The data analysis and research results show that the online procurement and inventory management technology based on the cloud computing system proposed in this paper can effectively promote the stable operation of procurement and inventory.