An anti-human PD-1 monoclonal antibody, and a preparation method therefor and an application thereof. The anti-human PD-1 monoclonal antibody has good bioactivity, can effectively bind with an extracellular region of a human PD-1 protein receptor, and can effectively seal PD-1 protein at protein level and cellular level and block the binding of the PD-1 protein with a ligand PD-L1, thereby effectively enhancing immunity. The monoclonal antibody can be applied independently or jointly with other antitumor drugs to tumor immunotherapy and the diagnosis and screening of patients with PD-L1 positive tumors; and the monoclonal antibody has a promising prospect in the preparation of drugs for treating tumors, resisting autoimmune diseases and the like.