•A new synthetic routes of Cu2−xSe/CuTi CE has been proposed.•Cu2−xSe/CuTi CE is fabricated by sacrifice template method.•The QDSCs based on the Cu2−xSe/CuTi CE achieves the PCE of 6.25%.•The enhanced photovoltaic performance could be attributed to the improving electrocatalytic activity.•The Cu2−xSe/CuTi CE shows excellent stability in polysulfide electrolyte. An efficient and simple strategy is designed for the synthesis of Cu2−xSe with two different morphology, including networks nanostructure and nanosheets structure, based on Ti substrate using a sacrificial template method (CuTi2S4 and Cu). The corresponding Cu2−xSe/CuTi CE and Cu2−xSe/Cu CE could be applied as counter electrodes (CE) for quantum dot sensitized solar cells (QDSCs). As a result, the cell fabricated by Cu2−xSe/CuTi-4 CE exhibits a photoelectric conversion efficiency (PCE) of 6.25% under 1 sun (100 mW/cm2) illumination as compared to that of Cu2−xSe/Cu CE (4.83%). According to transient photocurrent (TPC) result, the improving photovoltaic performance could be attributed to the improving electrocatalytic activity towards polysulfide electrolyte as compared to Cu2−xSe/Cu CE. These results are in accordance with the EIS analysis and Tafel polarization curve results for symmetrical cell. In addition, the outstanding stability of Cu2−xSe/CuTi CE could be further proved by cyclic voltammetry (CV) test. In conclusion, the Cu2−xSe/CuTi CE could be a promising material and the applications in solar cells.