The morphology of the perovskite film is one of the decisive factors for high-efficiency perovskite solar cells. This work fabricates the compact and high-coveraged perovskite film by using the isopropanol solution dissolved with the dimethyl sulfoxide and bromide methylamine to process the as-prepared perovskite films. The dimethyl sulfoxide can dissolve the perovskite grains and retard the grain reconstruction rate. The bromide methylamine can widen the band gap and improve the device performances by alternating the compositions to form the stable cubic phase perovskite.