The analog/digital acquisition module for intermediate frequency （IF） signal acquisition is the fundamental component of frequency-modulated continuous-wave （FMCW） lidar. Parameters such as the signal-to-noise ratio （SNR）， signal-to-noise and distortion ratio （SINAD）， and spurious-free dynamic range are major indicators of the alternating current characteristics of the data acquisition signal chain and directly determine the key indicators of FMCW lidar， including the detection range and ranging accuracy. First， this study designed an IF signal acquisition module for FMCW lidar， where the obtained SNR and SINAD were 49.13 dB and 48.90 dB， respectively. Second， the study investigated the noise characteristics of FMCW lidar， identified the system noise source as the phase noise of the sampling clock， and improved the SNR and SINAD by 11.38 dB and 11.32 dB， respectively， by introducing digital filters， which theoretically increased the detection range of FMCW lidar by 3.7 times. System noise can be reduced by using cosmetic clock chips， and the SNR can be improved by 8.65 dB. Finally， an optical phased-array FMCW lidar system was built to verify the effectiveness of the data sampling module and to conduct 40-m range distance detection under a maximum measurement error of 7.7 cm. The study determined that the FMCW lidar’s maximum detection range was 133.67 m.