Numerical model was developed to analyze photovoltaic parameters according to electronic properties of InGaN/GaN multiple quantum well solar cell (MQWSC) under hydrostatic pressure. Finite difference method was used to acquire energy eigenvalues and their corresponding eigenfunctions of InGaN/GaN MQWSC and hole eigenstates were calculated using a 6  ×  6 k.p method under an applied hydrostatic pressure. Our results show that depth of quantum wells, bandgaps, band offset, electron, and hole density increase with the increase in the hydrostatic pressure. Also as pressure was increased, electron and hole wave functions had less overlap, amplitude of absorption coefficient was increased, and binding energy of excitons was decreased. A change in pressure of up to 10 GPa caused absorption coefficient’s peaks of light and heavy holes to shift to low wavelengths of up to 32 nm, along with decreased current density of short circuit, increased open circuit voltage, and enhanced efficiency of InGaN/GaN MQWSC.