The effects of high temperature and pressure on the fluorescence of pyrophyllite have been studied. It is found that the wave numbers of the two peaks at 14 428 cm-1 and 14 398 cm-1 decrease under high temperature and pressure respectively. When high temperature and pressure are exerted on pyrophyllite simultaneously, the decrease is much smaller than those when they are exerted separately. Only at the place closest to the synthesizing chamber, pyrophyllite transforms into a new state with the effects of both high pressure and temperature. It is believed that the pressure and temperature change the electron energy levels which make a change of the transition energy.