The dependences of luminescence peak shift and relative emission intensity of (Zn0.85Cd0.15)S:Cu, Al phosphor on hydrostatic pressure have been studied at room temperature with a high-pressure microspectroscopic system in conjunction with the gasketed diamond anvil cell, using the methanal ethanal mixture as pressure liquid, the hydrostatic pressure ranging 1bar-66 kbar was monitored by ruby R-line shift. The emission peak E(r) of (Zn0.85Cd0.15)S:Cu, Al shift to higher energy with increasing pressure, dE(r)/dP=4:.7 meV/kbar (38 cm-1/kbar), but less strongly than does the absorption edge of the host. The relative emission intensity decreases strongly with increasing pressure, decreasing by 6% when pressure increasing from 1bar to 66 kbar. The results can be explained in terms of Al3+-Cu+ donor-acceptor pair model. Finally, we estimate that dED(Al3+)/dP+dEA(Cu+)/dP=3.7 meV/kbar (30cm-1/kbar).