Secondary Electron(SE) spectrum can be measured by energy analyzer which is equipped on a newly-installed Ultra High Vaccum(UHV) measurement facility. True-secondary electrons and backscattered electrons can be distinguished from emitted electrons, and true-secondary electron yield can be measured by integral of SE spectrum. In this paper, an experiment was carried out on pure silver material to compare Secondary Electron Yield(SEY) by different methods(electrical current measurements and SE spectrum analysis). The comparison result shows that the error of the two methods is less than 6%, which validates the electrical current method. The cause of error is also been discussed.