Metal-halide perovskite of MAPbBr3, by exhibiting several remarkable optoproperties such as tunable energy bandgap, high absorption coefficients, high color purity, and long charge carrier diffusion lengths, has made great contributions to photovoltaic and electroluminescent (EL) technologies, i.e., solar cell, photodetector, light-emitting diode, and newly developed bifunctional optoelectronics. To realize high performance bifunctional optoelectronics, it is imperative to promote the balance of the trade-off between effective radiative recombination during EL process and fast exciton dissociation in photodetective process. Herein, we optimize the crystallization and nanostructured surface of MAPbBr3 film through applying multistep vapour assisted deposition (MVAD) method. Then, we enhance the optical field distribution and charge transfer feature of MAPbBr3 film by establishing an optical simulation model. Based on our modifed MAPbBr3 active layer, finally, we demonstrate a high performance device with EL and ultraviolet photodetective bifunctions, which exhibits a 6.27-fold improvement of brightness and a 3 orders of magnitude increase of detectivity. To the best of our knowledge, this work not only reports high bifunctional perovskite optoelectronics performance, but also illustrates the optical field redistribution process in horizontal orientation surface of MAPbBr3 films for relevant researchers.