In order to monitor forest fires， a high-repetition-rate polarization lidar system was developed based on the light scattering and polarization effects of smoke particles generated during fires. The system consists of subsystems for laser emission， optical reception， Echo signal acquisition and processing， and scanning control. To meet the requirements of large-scale， high-resolution， and time-sensitive forest fire detection， a high-power， high-repetition-rate laser was selected as the detection source， combined with a high-angular-resolution gimbal to enable precise scanning. At a lidar repetition frequency of 5 kHz， the system can perform patrol scanning of a forest area with a 10 km radius in 48 minutes with an angular resolution of 1°. To address the challenges of echo signal acquisition and cumulative averaging during high-repetition-rate detection， a novel and dedicated “readout-accumulation-storage” IP （Intellectual Property） architecture was designed， efficiently achieving echo signal acquisition and improving the signal-to-noise ratio. The completed high-repetition-rate polarization lidar underwent near- and far-field simulation experiments， with detected peak points aligning with fire locations. Deployed in Yan’an City， the lidar successfully detected simulated fires at distances of 5.4 km and 8.1 km， validating the system’s effective detection capability.