The present invention relates to the biomedicine field, in particular to an anti-human PD-L1 humanized monoclonal antibody and its applications. The invention obtains an anti-human PD-L1 humanized monoclonal antibody with good specificity, high affinity and stability by screening, and the antibody can specifically bind to human PD-L1 instead of binding to members of B7 family, and it can bind to active T-cells to strengthen the activation of T-cells, so it can significantly inhibit the growth of tumor.