In the domain of single-photon laser radar target detection, the current detection speed is relatively sluggish. In order to address this limitation, a Fast Constant False-Alarm Rate (F-CFAR) detection method is proposed in this paper. Firstly, the data format of the single photon lidar signal is redesigned according to the characteristics of the radar echo signal. Then reduced the noise intensity through data processing. Finally, the constant false alarm detection is carried out on the processed signal data. This method can improve the detection speed without excessively reducing the detection performance. Simulation and experiment show that, the proposed method achieves at least an order of magnitude improvement in target detection speed compared to traditional signal detection methods, while maintaining relatively stable detection performance.