Efficient　ternary　organic　solar　cells　were　achieved　by　utilizing　an　ultra-narrow　bandgap　material,　IEICO-4　F,　mixed　with　the　fullerene　material　PC71BM　as　the　acceptor　and　PTB7-Th　polymer　as　the　donor.　The　different　weights　of　IEICO-4　F　were　dropped　into　the　active　layer　to　adjust　the　ratio　of　acceptor　and　donor,　optimizing　the　performance　of　the　cells.　The　results　showed　the　ternary　organic　solar　cells　with　10wt%　IEICO-4　F　could　obtain　a　higher　short-circuit　current　density　resulting　in　the　power　conversion　efficiency　(PCE)　up　to　9.56%.　MoO3/Ag/MoO3　as　the　transparent　electrodes　of　the　semitransparent　organic　solar　cell　(ST-OSCs)　were　prepared.　The　different　thicknesses　of　Ag　impacts　on　the　performance　of　the　ST-OSCs　were　investigated.　The　PCE　of　the　ternary　ST-OSCs　was　increased　to　7.34%　and　the　average　visible　light　transmittance　(AVT)　was　increased　to　28.74%　when　Ag　was　10　nm　thickness.　The　ternary　ST-OSCs　presented　both　a　good　light　transmittance　and　a　high　PCE.　In　addition,　the　light　utilization　efficiency　of　the　ST-OSCs　was　increased　to　2.1%,　and　the　color　reproduction　index　was　improved　too.　The　PCE　and　AVT　of　the　ST-OSCs　could　improve　simultaneously　due　to　the　appropriate　ratio　of　the　acceptor　and　donor　as　well　as　the　optimized　transparent　electrodes.