A nitrogen-free and slot-die coating fabrication of perovskite solar cells combined with NIR annealing. We develop a fabrication approach of planar inverted structured perovskite solar cell (PSC) in ambient condition with a PCE of 12.4% as compared to that (13.3%) of PSC fabricated in glove box filled with nitrogen. In addition, we demonstrate an alternative post-annealed method by near-infrared (NIR) radiation to traditional heating method by oven. The annealed time by NIR can be shortened from 1500 s to 30 s and the device performance over 10% can be achieved. The present work investigates the NIR effect for different layers in the two-step processing on the cell performance. The grazing-incidence wide-angle and small-angle X-ray scattering (GIWAXS and GISAXS) techniques for the perovskite layers are performed to reveal the crystalline and nano-morphological structures of perovskite layers correlated to thermal and NIR annealing effects. Based on this approach under ambient air, we scale up to the large-area fabrication using the slot-die coating. The performance of slot-die coated PSC can achieve to 12.3%. The critical step is the control of PbI2 layer thickness. We also applied the NIR radiation to the slot-die coated PSC and the PCE of 11.4% can be achieved. Our study paves a facile way to rapid manufacture and mass production of perovskite solar cells.