CsPbBr3 perovskite quantum dots were prepared by room temperature synthesis, and the surface ligand density was controlled by the cleaning times. By preparing the device structure as ITO/PEDOT∶PSS/PTAA/CsPbBr3 QD/TPBi/LiF/Al, the influence of cleaning times on the electroluminescent device was studied. The results show that when the quantum dots were cleaned twice, they can get balance between the charge injection and liquor stability, and a green perovskite QLED with a maximum brightness of 1405cd/m2, an external quantum efficiency of 0.6%, and a color coordinate of (0.127,0.559) was obtained.