“十五”期间,在全国各地震台站共安装了约12套ELF极低频电磁观测仪器,从记录到的观测资料来看,所有台站均不同程度地受到工频50 Hz及其谐波的干扰,同时还有一些不必要的信息存在,因此,对ELF观测数据进行滤波处理显得尤其重要。该文用MATLAB编程软件设计了FIR数字滤波器,运用理论数据和ELF实测数据对滤波器的性能进行了验证,分析了ELF时间序列经过带通滤波和陷波处理后的效果,发现其对台站ELF观测数据的处理有一定的应用价值。 During the “Tenth Five-Year Plan” period, about 12 sets of ELF ELF instruments were installed at stations around the country. According to the observed data, all stations were affected to varying degrees by 50 Hz and its Harmonic interference, but also some unnecessary information exists, therefore, the ELF observation data filtering is particularly important. In this paper, the FIR digital filter is designed by MATLAB programming software. The performance of the filter is verified by theoretical data and ELF measured data. The effect of ELF time series after band-pass filtering and notch processing is analyzed. The processing of station ELF observation data has certain application value.