Based on Web Service and Multi-agents technology, this paper proposes to build a remote distributed fault diagnosis system for equipments of an incineration plant which requires real-time diagnosis in a widely distributed environment. The system is modeled and implemented by multi-agent technology and is composed of a large number of agents, which are deployed at different web sites. To extend system capabilities, a user can provide additional diagnosis procedures, diagnosis services or data services. Based on diagnosis goals, relevant agents are assembled together to form a remote collaborative diagnosis system. The system can be used in any incineration plants, which greatly simplifies the deployment and maintenance efforts.