On the basis of the experimentally synthesized WD8 dye, a series of new metal-free dual donor type ME301-ME306 dyes were designed. Both Density Functional Theory (DFT) and Time-dependent Density Functional Theory (TDDFT) were used to further investigate their physical and electronic properties including their molecular structures, IR spectra, energy levels and Light Harvesting Efficiency (LHE). The results showed that the double fluorene donors in ME302 were more promising functional groups. In particular, compared with WD8 dye, ME306 not only had its higher molar extinction coefficient and 50 nm red shift, but also covered the entire visible light range and had a broader absorption spectrum. In addition, ME306 could inject electrons into the TiO2 electrode successfully. The design of this double donor dye could provide new strategies and guidance for the research on high efficiency dye-sensitized cells.