There is a strong single frequency interference wave around 50 Hz in seismic records when a high-tension line crosses over a seismic line in the process of field seismic data acquisition.The authors studied the interference wave using sine wave in time domain and subtracted it from seismic records for the purpose of suppressing the interference wave.Theoretical and real data results prove the feasibility of the method in suppression of strong single frequency which is unlikely to be suppressed by conventional filtering methods.The most major advantage of the method lies in the fact that only the interference wave with single frequency can be suppressed,and the loss of useful signal is very limited.