[en] The cylindrical cavity is needed to realize inertial confinement fusion (ICF) via an indirect driving mode, which will generate abundant plasmas and hot electrons when the laser irradiates cavity at the ShenGuang-III laser facility, leading to radiation of intensive electromagnetic pulses (EMP) inside and outside the laser chamber. It is thus significant to reveal the relationship between the EMP’s intensity and distribution with laser parameters since it can be helpful to understand ICF and benefits shielding design to protect various diagnostics. The EMP intensity decreased with the size of the cylindrical cavity chamber, which was also confirmed by the simulating results obtained by developing a cylindrical model with different sizes. (paper)