At present, mature technology of images fusion is generally implemented by software. But it has been proved to have a bad real-time capability. This paper designs a new system to resolve the problems of bad real time performance on traditional method. Based upon FPGA, the system processes the infrared and low-level-light images then output images data to the display module in real time. In order to meet requirement of accuracy and optimization, this system takes a registration method based on parallel optical axis. Also, it adopts the bionic algorithm for color fusion of infrared and low Level light images. The images resultant increased by an average of 3.86% and 8.77% than Waxman algorithm in terms of mutual information and structural similarity respectively. The exceptional quality images we can obtain shows that the system is useful in images processing. The processing and transferring time of one frame image is 0.043434s in total shows that the system performs better in real-time. In addition, this system is valuable for defense and security.