This paper concerns the operations analysis of the high power EMP-bomb. The main influence factors of antenna radiant power's space distribution were analyzed. The space distribution of the high power EMP-bomb was modeled. The formulas of power density in coverage area at the target's plane were deduced. The transmission attenuation model of electromagnetic energy was established. Lastly, the power density at the target location was simulated. It is shown that for the different posture of the targets and the bomb, the optimal pitching angle, azimuth angle and altitude were existed. The results can be used as important references to discuss the damage effectiveness of high power microwave.