In this study, triphenylamine-based dye sensitizers possessing dual D--A units with triphenylamine as an electron donor and thiophen-isocyanoacrylic acid as an electron acceptor (dye1 and dye2) were designed and investigated in comparison with a reference dye based on dianchoring D--A units (BPDTA). Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations of these dyes were performed to understand the factors influencing the photovoltaic efficiency. The absorption spectrum of the dyes showed different forms because of the different energy levels of the molecular orbital (MO) of each dye and the intramolecular charge transfer (ICT) characteristics. Dye2 showed a broader and more bathochromically shifted absorption band than the other dyes. It also showed a higher molar extinction coefficient than BPDTA. This work suggests that optimizing the chain of electron donors and acceptors in dye sensitizers based on dianchoring dual D--A units would produce dye-sensitized solar cells (DSSCs) with good photovoltaic properties.