Abstract: The number of radar, communication device and other radio equipment in various frequency bands integrated on a single platform of modern weapons is increasing, and the transmitting signals are developing to the direction of high power and ultral- wideband. The transmitting frequency spectrum between radar and other equipment overlaps seriously, leading to serious electromagnetic interference problems between different equipments. In this paper, the electromagnetic interference problems between transmitting and receiving signals of different radio equipments are analyzed, and the generation mechanism and improvement method of the out-of-band spectrum component of digital T/ R module pulse transmission are discussed. The specific spectrum control measures are proposed, and experimental verification is conducted on a certain radar digital T/ R module, proving the effectiveness of the proposed spectrum control method.