Abstract: A method of ionosphere delay calibration is proposed for real time interferometric tracking with sparse calibration mode,in order to realize high accuracy tracking in Chang'E-4 relay satellite mission. The theory of ionosphere delay is analyzed, then, diurnal character of TEC (Total Electron Content) is testified with instrumental data observeded in deep space stations. Based on the above discussion,software in deep space interferometric tracking center is updated. Experimental result testifies the effectiveness of the method,where delay observable accuracy is improved by 1~3 ns,especially in low elevation angle case. The method in this paper benefits the application in real-time tracking with deep space stations.