Abstract: Aiming at the problems of fieldbus device integration and system integration in the fieldbus system,the characteristics of FDT(field device tool) technology are studied.Based on the analysis,FDT technology is applied to the NCS4000 system in order to satisfy the requirements of the device integrating-management,and the software framework model and the integration model of the system are presented.The implementation method of the gateway DTM(device type manager) is explained in details,and the interaction process between the DTM program and the field device is analyzed.By developing the DTM and integrating it into the system,the feasibility of the design is verified.