In order to solve the problems of low brightness and loss of details inimages under low illumination environment, an improved low illumination image enhancement algorithm based on FPGA is designed and implemented. Based on the LIME algorithm, this study improves the original algorithm by introducing bilateral filter and YCrCb color space optimization method, which enhances the brightness and naturalness of the image while effectively retaining the edge information of the image. The RTL design of the improved algorithm is completed by Verilog language and hardware testing is carried out on FPGA development board. The results show that the improved algorithm performs well in brightness enhancement, contrast enhancement and image naturalness preservation, and is suitable for scenes with high real-time processing requirements.