宁东至山东±660kV直流输电示范工程的试验和运行，对山东很多台站地磁观测造成影响。就此分析高压直流对地磁观测的影响机制，计算影响幅度，提出地磁预处理方法（如曲线形态的对比、识别干扰的原则、干扰幅度的确定的原则等），为直流输电影响全国地磁观测问题提供解决思路。

 ± 660kV DC transmission demonstration project which is from Ningdong to Shandong had been tested and run, which influences Geomagnetic observation of many stations in Shandong Province .Therefore, the Analysis of influence mechanism of geomagnetic observations by high-voltage DC , the calculation of the impact of magnitude and the proposal of the geomagnetic pretreatment methods(such as comparison of Curve shape 、the principle of recognization of interference、the dmissetermination of the interference amplitude and so on) offered some beneficial thoughtway to the influence of direct current transiting on geomagnetic observation in our country.