The design of phase frequency detector and charge pump used in the phase-locked loop system has been achieved in this paper. The sampling period is divided into odd and even to avoid the overlap problem caused by the excessive reset delay signal. The phase frequency detector is divided into odd and even period by the data selector. The structure of the source-switch charge pump is adopted, and an operational amplifier is added to the structure to improve the matching characteristics and output voltage range of the charge pump. The circuit designed by TSMC N28 nm CMOS was simulated and verified in the Spectre. The simulation results show that when the output voltage of the charge pump circuit is 0~0.9 V, the charge and discharge current mismatch is less than 0.4%, and when the output voltage is 0.45 V, the charge and discharge current mismatch is only 0.028%; the frequency detector and the dynamic characteristic curve of the charge pump cascade simulation has good linearity, and when the two input signals phase of the frequency detector are same, the average output current of the charge pump is only -4.159 nA, which has good dynamic matching characteristics.