Abstract: The flood discharge power of Xiaowan hydropower station is large，and the observation results of the earth pulsation have a preliminary understanding on whether to cause the destructive force of earthquake level.According to the topographic condition of Xiaowan hydropower station，17 measuring points are set up，and the earth pulsation test was carried out.The test results show that the vertical direction and east-west direction of earth pulsation is relatively large，the north-south direction of earth pulsation is relatively small，but the overall influence is small.Except the dam body，the earth pulse peak acceleration is less than 1gal，pulse displacement RMS is substantially less than 1 μm，the frequency is less than 1 Hz，which belongs to low frequency vibration.The range of earth pulsation caused by flood discharge is within 900m，the center control building，building traffic hole vertical vibration acceleration level of VAL are 51.82dB，42.27dB，less than the allowable value of vibration comfort level 83dB.The rest were less than 83dB.It is judged that the earth pulsation of the flood discharge of Xiaowan hydropower station will not produce earthquake sensation.