Abstract: This paper put forward the practical method of realizing vibration sensor of ultra low frequency by means of magnetoelectric velometer. Using the tandem type correcting circuit, the measurable minimum frequency was reduced to less than 0.6Hz while the optimal damping was changeless. System analysis and discussion on the correcting circuit, working principle, transfer function and difference of the output characteristic before and after correcting of vibration sensor of ultra low frequency had been done.