Recent developments of PSCs have achieved great progress with power conversion efficiency reached to 22.1%. The crystal growth process as an important factor will significantly influence the quality of perovskite films and the device performance. In this paper, we demonstrate a simple approach for fast preparation based on the precursor compositions of (FAPbI(3))(0.85) (MAPbBr(3))(0.15) by regulating the temperature during annealing process for transition from FAI, PbI2, MABr, and PbBr2 to perovskite. The film will be shaped in 15 s for one-step deposition at annealing temperature of 220 degrees C. It has been found that higher temperature will induce perovskite to form larger size and oriented crystal grains rapidly. This will contribute to longer carrier lifetime and smaller carrier recombination which, are beneficial for solar cell device. The champion cell with PCE of 17.1% had been obtained measured under conditions of AM 1.5 G, 100 mW/cm(2). Furthermore, this method exhibits good stability which is benefited from large size crystal, the device will not be deteriorated and the PCE maintained over 90% after 3 months.