对消除电磁流量计信号中的工频干扰问题进行了分析和探讨。在理论上分析了不同的励磁频率、 采样点及宽度对测量精度的影响。经实际证明 ,利用理论分析的结果可以提高测量精度与加宽测量范围。-The question of 50 Hz power-line interference from electromagnetic flowmeter is discussed. Different exciting frequence , sampling spot and width are analyzed. By practical testifying ,it is proved that the conclusion has better performance with better accuracy and wider range.