Abstract: Facing to the demand of 10 Gbps transmission rate and 1cm ranging accuracy for laser communication, this paper designs and implements the main-control and communication ranging unit of laser communication terminal by using the system architecture of FPGA + integrated optical module and the ranging method of phase detector + high-precision ADC. Using two sets of principle prototypes of the unit, the ranging accuracy under differrent code rates is tested. The systematic error is effectively eliminated by recording the local clock time of the two prototypes sending and receiving measurement data frames. when the communication rate is 10 Gbps,the ranging accuracy of measurement distance is better than 1cm.This technology will be used for “National Internet Constellation” satellite laser communication terminal, and effectively improve the communication and ranging capability of laser link.