Abstract: A novel simulation technique of phased array target radar is introduced. Mechanical scanning radar is used to simulate the main-lobe fluctuation property of phased array radar, and trumpet array radar is used to simulate the side-lobe fluctuation property. By the time-sharing work of transmitters of mechanical scanning radar and trumpet radar array, the alternant radiation property of main lobe and side lobe in the space is simulated. This method realizes the realistic simulation of electromagnetic fluctuation property of phased array radar, and of the same time, the fabrication and maintenance cost is saved and the development period is shortened.