Time-to-digital converter (TDC) is a device for converting continuous time signal to digital signal, and it is the key component of TOF lidar. In this paper, designed is a two-stage coarse-fine combined time-to-digital converter circuit based on the traditional structure of counter coarse sampling and multi-phase interpolation fine sampling, and also a double echo receiving channel is added to receive multi-pulse echo signal. On this basis, a 17-channel multi-channel TDC system chip is designed. The system chip is designed with CMOS 0.11μm process, and the layout area is 0.6mm×3mm. The post simulation results show that the power consumption is less than 100mW, the average value of single input precision is 51.7ps, the dynamic range is 3.4μm, and chip presents good linearity under 1.2V power supply. Thus the TDC chip is suitable for signal timing of time-of-flight pulse lidar.