Abstract: The high-power pulse modulation is designed by combing electric exploding opening switch(EEOS)with gas switch with annular electrode.This circuit is designed to modulate the output of magnetic flux compression generator(MFCG). Firstly,the experiment to test the steepening effect of gas switches with electrode shapes in hemisphere,annular and flat with inverted round horn are carried out and analyzed.The high-speed breaking characteristic of EEOS is analyzed numerically and experimentally according to the relative of specific action and resistivity by software Pspice.At last,the experiment on the pulse modulation is made.The results show that when the charging voltage is 35 kV,the rising time of the pulse voltage obtained from the load is 1.68 ns,the peak value is 197 kV,and the energy is compressed by 5 times or more.The results from the simulation and experiment are roughly matched.It offers theoretical basis and experimental support for the joint experiment combing the pulse modulation circuit with the explosive magnetic flux compression generators.