Abstract: A molecule capable of binding to human 4-1BB includes the amino acid sequences of HCDR1, HCDR2 and HCDR3 in the heavy chain variable region of the antibody provided by present invention are shown sequentially at positions 31-35, positions 50-64, and positions 98-106 in SEQ ID No.1 from the N-terminus. The amino acid sequences of LCDR1, LCDR2 and LHCDR3 in the light chain variable region are shown sequentially at positions 24-34, positions 50-56, and positions 89-97 in SEQ ID No.2 from the N-terminus. The antibodies provided by the present invention can bind to human and monkey 4-1BB, exhibit high affinity to human 4-1BB and effectively enhance T cell responses; they can be used to regulate the immune responses mediated by T cells and antibodies; as immune modulators, they have a wide range of therapeutic uses in diseases such as cancer, autoimmune diseases, inflammatory diseases, and infectious diseases, etc.