Abstract: The constitution, technical features and working mode of the real-time onboard displaying system of Airborne SAR real-time digital imaging processor are studied systematically. And the special development of the display board under the real-time system is discussed. Further more the characteristics of the real-time operating system and its pSOS+ kernel that contitutes the software enviroment in the real-time dispaly system is presented. And also the multitasks scheduling management, communication and synchronization mechanisms applied in the real-time onboard diplay system are discussed.