The pi-pi stacking between molecules is one of the biggest obstacles preventing dye-sensitized solar cells (DSSCs) from achieving theoretical photovoltaic performance. By introducing rigid auxiliary groups on the donor, three unique self-inhibiting aggregation dyes ZS06, ZS07, and ZS08 were designed and synthesized. By comparing the absorption peaks of dyes in solution and on the TiO2 film, it can be concluded that the aggregation degree of these molecules is significantly weakened. In this study, the influence of different auxiliary groups on the main chain, including spatial structure, energy level, and light-harvesting ability, was investigated in detail. The results show that the advantage of this type of dye is that the auxiliary group has little effect on the light-harvesting ability of the molecule. By precisely regulating the shape and size of the auxiliary group, the best balance can be found between the loading amount and performance, thereby ensuring the maximum improvement of photovoltaic performance.