The present invention relates to combination use of PD-1 antibody and epigenetic modulating agent in the preparation of a medicament for the treatment of tumor. In particular, the present invention relates to combination use of PD-1 antibody and epigenetic modulating agent in the preparation of a medicament for the treatment of tumor or enhancing T-cell activity.本發明涉及PD-1抗體和表觀遺傳調節劑聯合在製備治療腫瘤的藥物中的用途。具體而言,本發明涉及PD-1抗體和表觀遺傳調節劑聯合在製備治療腫瘤和/或增強T-細胞活性的藥物中的用途。