Hybrid organic–inorganic perovskite materials have attracted a lot of attention with their facile synthesis process and high efficiency of light absorption. However, poor stability is always a big barrier to commercial development. In this study, a new kind of organic perovskites MA0.6(AA)0.4PbBr3 (AM-PE), which harnesses aniline as a replacement of conventionally used methylamine, was synthesized to increase the stability of MAPbBr3 (M-PE). The decomposition process of MAPbBr3 in acetone was investigated. Smaller PbBr2 particles were formed in the decomposition process, causing the change of photoluminescence emission wavelength from 540 nm to 610 nm. The photocatalysis and photoluminescence properties of M-PE and AM-PE were also compared. As a result, the introduction of aniline reduced the decomposition rate of AM-PE significantly and showed twice the catalysis efficiency of M-PE in the degradation of organic dye - malachite green.