The temperature and excitation-power-dependent photoluminescence (PL) spectra of In0.29Ga0.71As/GaAs multiple quantum wells (MQWs) grown by metal-organic chemical vapor deposition (MOCVD) were investigated. Through comparative analyses, the influence of localized states at low temperature on luminescence properties of materials was explored. And the PL measurement were carried out and used to study the influence of two different methods on the localized states and luminescence characteristics of the MQWs by changing the growth temperature of the sample of MQWs and rapid thermal annealing (RTA). The results show that when the growth temperature of the multiple quantum wells is high, the position peak of the PL exhibits a typical “S” shape in the range of 20–260 K, which indicated that the In segregation and the interaction between In and Ga were serious. Meanwhile, the localized states could be inhibition by lowering growth temperature of MQWs and adding the process of RTA. Both methods can further optimize the quality of the quantum well samples.