Abstract: The design and analysis of radar jamming signal is a main stream in radar countermeasures. This paper proposes a jamming method for pulse compression (PC) radar based on Multiple Phase Sectionalized Modulation (MPSM), and the signal’s coherence is partly kept and broke so as to achieve partial covering jamming effects. The principle of MPSM is elaborated at first, and the jamming signal’s generation is derived in details. Typical pulse compression radar using linear frequency modulation signals is raised as an example to illustrate the principle. Combined with the mathematical model of selfdefense jamming scene, the magnitudephase characteristics and pulse compression result of jamming signals are derived, and the impact on jamming covering scope by adjusting the MPSM parameters is analyzed. Finally, the simulation is conducted to prove the related conclusion above, and it is obvious that this jamming method can produce plenty of false targets flexibly and its covering scope is controllable,which is usable in practice.