With the development of smart grid, DG’s access to the power grid will affect the power quality, then harmonic, inter-harmonics and frequency fluctuation will appear in the grid, which will affect the accuracy ofSmeter. Aiming at the new requirements of smart meters of AMI, this paper study on complex bandpass filtering algorithm based on Gauss window function which possesses good time-frequency domain characteristics as the measurement algorithm of smart meter. Digital Signal Processor (DSP) can be used in smart meter, and the paper realized the algorithm by DSP. The results show that the algorithm can collect the various characteristic parameters of power measurements of smart meter during the presence of harmonic and inter harmonic, this method has good real-time performance,Sstrong anti-interference ability,Shigh precision,Sfast processing speedSand other advantages.