In this study, we developed a quaternary metal selenide (Fe0.35Ni0.11Co0.19Se) counter electrode (CE) material, grown onto fluorine-doped tin oxide, for dye-sensitized solar cells (DSSCs) using the potential-reversal electrochemical deposition technique at ambient conditions. Under optimized conditions, the Fe0.35Ni0.11Co0.19Se CE exhibited excellent electrocatalytic activity in the I-/I3- redox reaction with the average transmittance of 78.85%. The incorporation of additional valence states of Fe into the Ni0.3Co0.3Se electrode material further enhanced the catalytic activity during the electrochemical redox process. The DSSC employing this electrocatalytically active CE realized a power conversion efficiency of 7.73%, surpassing the efficiency of both Pt and Ni0.3Co0.3Se CEs-based DSSCs (7.23% and 7.23%, respectively). This electro-preparation method offers a simpler and more cost-effective fabrication process for CE design, demonstrating a good potential for replacing expensive platinum CEs in DSSCs.