By combining the demand for the integration of the fieldbus electric control system（FECS） and distributed control system（DCS） in the large-scale fuel power plant， the software architecture of the SCADA/HMI of FECS of fuel power plant is described， which is suitable for the application of process control in FCS. Some key technical points of the SCADA/HMI of FECS are also discussed. The microkernel real-time database， the soft-backbone and the process real-time database techniques are used to improve the performance of FECS. The software programmable logic control module based on IEC 61131-3 is also realized in FECS， which is used as a programmable automation controller（PAC）. Some self-diagnosing and self-adaptive techniques are adopted to improve the reliability of FECS. The development trend of the SCADA/HMI of FECS is analyzed.