Organo-lead perovskite materials as light harvesters have represented a hot field of research on high-efficiency perovskite solar cells. In such cells, the quality of organo-lead perovskite films is most critial to device performance, essentially affected by varying halide composition. Meanwhile, the understanding of formation mechanisms and basic properties of these hybrid perovskites is still ongoing. Herein, we report a one-step solution processing strategy to investigate the role of precursor in the context of hybrid perovskites, in which the molar ratio of the methylammonium compound and lead salts is closely correlated to the characteristics of the hybrid perovskite films. We investigate the molar ratio dependence of the mixed-halides incorporation of three organolead trihalide perovskite absorbers, CH3NH3PbI3-aBra, CH3NH3PbI3-aCla and CH3NH3PbBr3-aCla, and compare them with three pure (CH3NH3PbI3, CH3NH3PbBr3, and CH3NH3PbCl3) perovskites. We find the versatility of the hybrid perovskites affected by excess organic compounds. Specifically, the synergistic effect of the mixed-halides in tuning perovskite composition demonstrated that the different perovskite compositions deserved more in-depth understanding from with the varying of the crystal transformation, morphological framework, thermal decomposition and optical performance of the hybrid perovskites. Moreover, this work provides visual evidence for the design of the mixed halide perovskites based on these hybrids, which paves a way for improvements with selective properties in lead halide perovskite-based devices.