Compressed coded aperture based imaging warning system with a low resolution optical sensor is proposed in this paper, which is specifically designed to support the demands of rapid, high resolution, long-range detection and warning in complex battlefield environment. After analyzing of the tactic specification and the technical specification, the key techniques of this novel alarming system are discussed and designed, including optical imaging module, image-processing module, alarming control module and interfaces unit. The optical imaging module is used for image compression, then, the coded image will be mathematically reconstructed to a high resolution image by the image-processing module. The presented super-resolution reconstruction algorithm is efficient and robust. Combining compressed coded imaging simulation and coded image super-resolution reconstruction, experiments show that the compressed coded aperture imaging alarming system has a longer detectable range and higher resolution, which is potential in the defence of important targets.