To amplify the DC signal is a discommodious issue, because of the on-chip DC signal has such properties as little swing, less coherence and likeliness to be interfered. In light of this, a “voltage-frequency-voltage” mode DC signal amplifier is proposed, in which the frequency is the carrier signal. This amplifier is highly linear, and is equipped with a high linearity “voltage-frequency” modulator and a “frequency-voltage” de-modulator. The simulation experimental results show that the DC signal amplifier amplifies the input voltage signal efficiently while achieving stable high linearity, and the DC gain is 2.4.