All-inorganic perovskite quantum dots have wide application prospects in the fields of lighting and display. However, the photoluminescence quantum yields of violet-blue emission for the CsPbCl3 quantum dots is still low. In this work, the Rb+ ions were successfully incorporated into the lattice of CsPbCl3 quantum dots with partially substituting the sites of Cs+ ions by the modified hot injection method. It was interesting to observe that the photoluminescence quantum yields of CsPbCl3 quantum dots was improved from 5.7% to 13% through the optimization of Rb+ doping concentration. The absorption and emission peaks of CsPbCl3 quantum dots shifted to blue, originating from lattice substitution of Cs+ with R-b+. Further investigation on the photoluminescence dynamics of the quantum dots revealed that the enhanced photoluminescence quantum yields resulted from the reduced defects in CsPbCl3:Rb quantum dots. This work offers a new approach to improve the optical performance of perovskite quantum dots.