Organic-inorganic perovskite solar cells (PSCs) have achieved high power conversion efficiency (PCE) over the last few years. However, interfacial recombination of PSCs and the defects of perovskite film still seriously restrain the performance of PSCs. Hence, we introduced PbS quantum dots (QDs) between perovskite layer and hole transport layer (HTL) to modulate delicately both the interfacial contact and the perovskite film. With the incorporation of PbS QDs, the PSCs presented enhancement in hole extraction and retardation in interfacial recombination. Besides, proper concentration of PbS QDs contributed to improved perovskite film morphology by enlarging the grain size and healing the pinholes. Benefiting from all of these advantages, devices with PbS QDs modification achieved an impressive PCE of 19.24%, superior to that fabricated without the modification.