Because of the requirement of autonomous navigation, an integrated lidar of ranging and communication based on pseudorandom code modulation was proposed. The system had the advantages of low power consumption, small volume and multi-function. Adopting pseudorandom code, the lidar system realized the integration of ranging and communication. Adopting silicon photomultiplier (SiPM) to achieve photon counting realized the miniaturization of lidar system. The design principle, component, simulation, and the experiment result of the system were introduced in detail. The result shows that the maximum detection range can reach 1 km for the target with 0.1 reflectivity under daylight, and the range resolution is less than 1 m. The maximum communication range can reach 3.7 km with 10 kbps code rate and error rate less than 10-5.