Recently, ternary organic solar cells have emerged as a promising strategy to achieve both high performance and fabrication simplicity for organic solar cells. It has been proved that this strategy is an effective way to achieve improved short-circuit current density (J sc) with complementary absorption or to get enhanced open-circuit voltage (V oc) through forming energy level cascade. In this work, we designed and synthesized a thieno [3, 2-b] thiphene-substituted porphyrin molecule flanked with two diketopyrrolopyrrole units by ethynylene bridges, named DEP-TT, which exhibited a very low energy bandgap of 1.31 eV and a broad light absorption to 898 nm. The power conversion efficiency (PCE) of binary devices based on DEP-TT and the acceptor [6, 6]-phenyl-C71-butyric-acid-methyl-ester (PC 71 BM) achieved 7.46% with a relatively low V oc of 0.75 V. Futhermore, the ternary solar cells with 10% indene-C60 bis-adduct (ICBA) achieved high PCE of 8.15%, with higher V oc, J sc and a relatively higher PCE based on organic solar cells with a porphyrin-small molecule as the donor. This improved performance is believed to be due to the energy level cascade and synergistic effects of the two acceptors of PCBM and ICBA, which suggestes that the ternary bulk heterojunction (BHJ) strategy is a promising way to improve both V oc and J sc simultaneously and thus overall performance for the same donor material.