The quality of the photoactive layer gravely affects the characteristics and stabilities of photovoltaic device. Here, by introducing polyethylene glycol (PEG) into the methylammonium lead trihalide (MAPbI3) precursor solution, we fabricate high-quality MAPbI3perovskite film with high coverage and large grain size. By adjusting the PEG concentration into the perovskite film, the hole-conductor-free mesoporous perovskite solar cell with carbon electrode exhibits a boosted power conversion efficiency of 11.62%, which originates primarily from the enhancements of light absorption and acceleration of carriers transfer. Meanwhile, hygroscopic PEG protects the perovskite film from moisture, which leads to the perovskite film and corresponding device exhibit superior stability. This work confirms a high-efficiency and feasible strategy using polymer materials to enhance the performance in power conversion efficiency and stability of perovskite solar cells. [All rights reserved Elsevier].