The present disclosure belongs to the technical field of intrusion detection, specifically provides an intrusion detection method based on an improved immune network algorithm, and an application thereof The method includes: S1, initializing an antibody group; S2, calculating affinities between antigens and antibodies; S3, searching for a pair of inhomogeneous antigens which have the highest affinities and referred to as a duality antigen; S4, determining a boundary antibody set C; S5, determining a neighbor antibody set; S6, cloning and mutating, according to the affinities, obsolete antibodies to update a subnetwork to which the antigens belong; S7, calculating an average affinity between the antibodies in the boundary antibody set C and the antigens in the duality antigen; and S8, inhibiting the network, and simplifying the network to output a result network subset. The solution has relatively high detection accuracy and relatively low false alarm rate.