The single anti-ship missile guidance system has not met the requirements of the modern sea warfare, so it is very important to develop the multi-mode compound seeker, to improve the target recognizing, anti-disturbing and penetrating ability for the anti-ship missile. Aiming at active radar/infrared imaging compound guidance, the features of the non -common aperture and common aperture technology are discussed. The coaxial and common aperture is the ideal method and the development direction. The target acquisition and tracking can be realized under the complex conditions by the time and space registration, fusion detection, data association, fusion identification and fusion tracking.