The wide-band gap organic material PTB7-Th： PC₇₁BM was used as the front cell， the narrow-band gap organic material PTB7-Th： IEICO-4F was used as the rear cell， and the MoO₃/Au/ZnO film was used as the interconnecting layer （ICL） to fabricate a tandem cell. MoO₃ / Au / ZnO film was prepared by evaporation and sputtering， which not only had high light transmittance， but also good resistance to solvent erosion. In addition， in order to further reduce the erosion of the solution to the front cell when the cell active layer was spin-coated， chloroform with a low boiling point was selected as the solvent of the rear cell and the dynamic spin coating method was used to reduce the solvent volatilization time. Finally， a tandem organic solar cell with the power conversion efficiency （PCE） of 9.35 % was obtained， which had higher PCE and an open circuit voltage （V_oc） of up to 1.4 V compared with single-junction organic solar cells. The results showed that MoO₃/Au/ZnO thin films could have great advantages in the preparation of tandem solar cells.