A construction scheme of semi－physical simulation system for a laser－guided bomb seeker is presented. The system consists of optical simulator, fuselage attitude simulator, simulation computer system, integrated control equipment, interface communication equipment, display and monitor system and master control. The optical simulator includes diffuse reflector, target simulator, interference simulator and background simulator. The three－axis turntable is the main unit of the attitude simulator. The demands of its sub－systems are analyzed and their constructions are discussed in detail.