Using diamond anvil cells, the photoluminescence (PL) spectra of InxGa(1-x)As/AluGa(1-y).As (x, y = 0.15, 0; 0.15, 0.33; 0, 0.33) multiple quantum wells (MoWs) with well widths from 1.7 to 11.0nm were measured at 77K under highpressure up to 4GPa. The experimental results show that the pressure coefficients of the exciton peaks corresponding to transitions from the first conduction subband to the heavy-hole subband decrease with increasing wen width for in0.15Ga0.85As/GaAs MoWs. However, the corresponding pressure coefficients increase for In0.15Ga0.85As/Al0.33Ga0.67As and GaAs/Af0.33Ga0.67As MQWs, respectively. Calculations based on the Kroulg-Penney model reveal that the increased or decreased conductionfoand offsets and the increased effective masses of electrons with increasing pressure are the maill reasons of the change in the pressure coefficiellts.