The present invention discloses a small molecule PD-1/PD-L1 inhibitor, a pharmaceutical composition thereof with a PD-L1 antibody, and applications thereof; wherein the small molecule PD-1/PD-L1 inhibitor is, for example, an aromatic vinyl or an aromatic ethyl derivative represented by the formula (I), which can be applied to cancer treatment.本發明公開了一種小分子PD-1/PD-L1抑制劑、其與PD-L1抗體的藥物組合物及其應用。其中,該小分子PD-1/PD-L1抑制劑例如通式(I)所示的芳香乙烯或芳香乙基類衍生物,其可以用於治療癌症。