Abstract: This paper analyses the basic principle of Doppler beam sharping radaf imaging and it's real-lime signal processing procedure,on the basis of Doppler resolution theory,Then, a real-time digital signal processing scheme of Dopoler beam sharping is developed. Computer simulation results show that the Doppler beam sharpened ratio of the system can reach 17.4 :1 ,a large area of sector radar image with high resolution can also be provided within the range of an angle of ±150°-600° in front of airborne radar when the radar antenna keeps uniform scanning speed.