This paper analyzes the low-level-light image and ultraviolet image's characteristics, and then the low-level-light and ultraviolet dual band false color preprocessing and fusion hardware system is put forward. To this system, real-time performance is an important factor. This system contains two parts. The first part is a FPGA+SDRAM architecture noise reducing system. The time domain average filter is applied to this part, because it meets the real-time requirement and can effectively decrease the low-light-level and ultraviolet image's flicker noise. The second part is the fusion system. Its core is the most advanced video processor TMS320C6711. The processor's EDMA can operate smartly to achieve the dual channel images' capturing, calibrating and false color displaying without the core processor's interference, while this trait is especially useful to the dual band image fusion system. In this part, for real-time performance consideration, the improved gray modulating fusion algorithm is used. The improvements aim at using the maximum potential of the core processor's architecture. This paper gives the hardware data flow of the time domain average filter algorithm, the image registration algorithm and the improved gray modulating fusion algorithm in detail, and the system's schematic is also included in this paper. This system achieves the low-level-light and ultraviolet image's noise reducing, and solves the worldwide problem, the image registration. And most important it is a real-time hardware processing system and can be easy to integrate and equip.