Because of large amount of data and real-time characteristics, the processing of the signal of a laser Doppler velocity radar needs a high performance processing module. The Field Programmable Gate Array (FPGA) with advantages of high speed and parallelism can meet this demand. The implementation of signal processing for a laser Doppler velocity radar with a FPGA chip is presented. The data buffer, interference frequency filtering, 2-fold down-sampling, Fast Fourier Transform (FFT) and pulse accumulating etc of the FPGA are described. Finally, the performance of the module is analyzed and its test result is given.