The invention discloses a high-efficiency organic solar cell based on poly(3-hexylthiophene), which comprises a substrate, a cathode, a cathode modification layer, an active layer, an anode modification layer and an anode, wherein the active layer is an electron donor and A blend film of electron acceptor, the electron donor is poly(3‑hexylthiophene) (P3HT), and the electron acceptor is the non-fullerene acceptor DFPCBR. Utilizing the large π-conjugated system and strong electron-donating properties of the central unit, DFPCBR has high HOMO energy levels and LUMO energy levels, which form a good match with the energy levels of P3HT, suppressing energy loss, and making solar cells have higher open circuit voltage. At the same time, the intramolecular charge transfer (ICT) of DFPCBR is enhanced, which narrows the band gap and broadens the absorption spectrum. Therefore, the organic solar cell prepared by the invention obtains a relatively high power conversion efficiency (PCE), the highest being 5.34%. At the same time, the organic solar cell prepared by the invention can still maintain a high PCE even when the active layer is relatively thick, which is beneficial to future practical applications.