The experiment of 1 MeV electron beam irradiating undoped In0.22Ga0.78As/GaAs quantum well material with electron dose of 1×1016/cm2 is conducted. The experimental results indicate that, when quantum well material irradiated, the defects occur as a result of energy transfer in the material which degrades the photoluminescence. As for the irradiated quantum wells, the stress relaxation and atom intermixing coexist which result in the photoluminescence peak first red-shifting and then blue-shifting, and their photoluminescence wavelengths are determined by the coaction of strain relaxation and diffusion.