Organic-inorganic halide perovskite solar cells have achieved efficiency over 23% in the last few years. However, most perovskite solar cells have been fabricated by lab-scale spin-coating method and the strategy for the doctor-bladed device improvement is quite limited. In this study, we report an additive-assisted strategy enabled by Poly(acrylic acid) molecular doping to connect wide gaps between the large domains and passivate defects in the bladed perovskite film. Using this strategy, we obtain a smooth, uniform, and pin-hole free doctor-bladed perovskite film of high electronical quality, which are proved by detailed laser spectroscopy. Consequently, the P-i-N planar heterojunction perovskite solar cells with these bladed thin films achieve considerable enhancement of power conversion efficiency from 10.3% to 14.9% compared to the control device. This work represents an alternative pathway for scalable, cost-effective manufacturing of high performance perovskite devices.