The invention belongs to the technical field of biology, and relates to a hybridoma cell strain and an antibody secreted by the hybridoma cell strain, in particular to the hybridoma cell strain of a monoclonal antibody resisting porcine delta coronavirus (PDCoV) N protein epitope, the antibody secreted by the hybridoma cell strain and application of the monoclonal antibody. The amino acid sequence of the antigen epitope is 326-QDWEWDDA-333, the hybridoma cell strain is classified and named as hybridoma cell strain PDCoV-N-6B7, the preservation number is CCTCC NO: C202178, the preservation date is 2021.3. 26, and the preservation address is Wuhan University, Wuhan, China. The antigen epitope of the 6B7 monoclonal antibody is high in conservative property, is a linear epitope, belongs to an immunodominant epitope, and is beneficial to antibody combination in serum to be detected, so that establishment of a blocking ELISA kit by using the monoclonal antibody aiming at the epitope is more sensitive.