The invention discloses a phase-locked loop circuit used for inhibiting a VCO (voltage-controlled oscillator) voltage ripple, which comprises a frequency-phase detector, a charge pump, an automatic frequency band selector, a loop filter, a voltage-controlled oscillator, a frequency divider and a first transmission gate. In the invention, as the transmission gate is used as a mode-converting switch, the VCO control voltage ripple caused by traditional MOS (metal-oxide semiconductor) transistor in different working models converting in the phase-locked loop, the electric charge injection and the clock feed-through are reduced, thus, the purpose of inhibiting the VCO voltage ripple is achieved. Meanwhile, the transmission gate is embedded in the third order loop filter, thus, the converting of different working models of the phase-locked loop is realized, and an onstate resistor of the transmission gate is utilized as the resistor of the third order loop filter, the noise is effectively filtered, and the VCO voltage ripple caused by the noise is greatly reduced.