Because electric parameters are crucial for indicating the operating condition of power generation equipment, an intelligent instrument for electric parameters measurement of power generation equipment was developed. A Hanning windowing interpolation algorithm based on FFT and a hardware frequency track were adopted to reduce the effect of leakage and fencing. In addition, a high speed AD conversion based on an external bus interface, a multiple feedback filter, an application of μC/GUI, and a multitask scheduler all were designed to improve timing and antijamming. Test results indicate the system is stable and easily operated. The measured relative error of electric parameter is less than 0.5%.