The effects of various parameters on the effective refractive index of TE mode and TM mode of multiple quantum well materials are analyzed. The results show that when the number of wells increases, the effective refractive index of multiple quantum wells decreases. When the number of quantum wells is more than 3, the change of the effective refractive index is not obvious. As the barrier thickness increases, the effective refractive index decreases slightly. There is a suitable amount of tensile strain to make the peak wavelengths of effective refractive index of TE mode and TM mode close, meanwhile the difference between the refractive indices is the smallest as a whole, and the polarization dependence is the smallest. Based on the above analysis, a design method is proposed to realize low polarization dependence of effective refractive index of multiple quantum well and a multiple-quantum well InGaAs/InGaAsP with low polarization dependence of refractive index within C-band (1530-1565 nm) is designed. The research result is helpful for designing practical quantum well materials with low polarization dependence of effective refractive index.