The paper introduces a high-performance multifunctional apparatus for studying secondary electron emission characteristics of dielectric. The apparatus is equipped with a collector containing three grids and a 30 eV?30 keV electron gun, the secondary electron emission characteristics of dielectric can be measured under ultra-high vacuum, and in-situ XPS analysis spectrometer, heating and argon ion sputtering can also be performed. The paper also introduces the measurement of secondary electron yield by pulse method, gives the measured secondary electron current pulse of gold and Al₂O₃, presents the charging saturation time and influence of the thickness of dielectric on the charge amount obtained by judging the change of the current pulse waveform with time and the number of irradiations.