Three donor-π-acceptor (D-π-A) dyes (P1–P3) of polymeric metal complexes were synthesized for application in dye-sensitized solar cells (DSSCs). These D-π-A sensitizers use Phenothiazine appended with octyl as donor (D), C=C bond as π-bridge(π), and thiophene-phenanthroline metal complexes as acceptor (A) that can be anchored to the TiO2 surface. They have been characterized and studied by FT-IR, GPC, Elemental analysis, TGA, UV-vis absorption spectroscopy, photoluminescence spectroscopy and cyclic voltammetry. When applied in the DSSCs, the sensitizer P1 exhibits the best energy conversion efficiency of 1.57% (Jsc = 4.12 mA/cm2, Voc = 0.62 V, FF = 61.7%) under simulate AM 1.5G solar irradiation. The TGA data show that these new dyes own good thermal stability. These results will facilitate the understanding of the crucial importance of molecular engineering and pave a new path to design novel conjugated organic polymer dye for highly efficient and stable DSSCs. Three D-π-A sensitizers that use Phenothiazine appended with octyl as donor, C=C bond as π-bridge, and thiophene-phenanthroline metal complex as acceptor were synthesized. When applied in a dye sensitized solar cell, the sensitizer P1 exhibits the best energy conversion efficiency of 1.57% under simulated AM 1.5G solar irradiation.