Inactivated PEDV （0.5 mg/mL） encapsulated with different concentrations of chitosan-catechol（Chic） including 0.2 mg/mL and 0.4 mg/mL named as C1+P and C2+P was prepared by controlling the amount of Chic， and a mouse model was established for immunization testing to evaluate the oral immunization efficacy of inactivated porcine epidemic diarrhea virus （PEDV） vaccine modified with Chic. Indirect enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of sIgA in mouse mucosa and IgG， IgG1， IgG2a antibodies in serum. Flow cytometry and CCK-8 assay were used to detect the phenotyping and proliferation activation of spleen cells. The results showed that the immune response induced by the C2+P group was comparable to that of the expensive cholera toxin B subunit （CTB） adjuvant group after two oral immunizations. Compared with the PEDV group without Chic modification， the antibody titer of nasal，lung，and small intestine mucosa-specific sIgA in the C1+P group and C2+P group was increased by 6.09， 6.37 times， and 5.35， 5.65 times， and 5.64， 5.89 times， respectively. The serum specific IgG， IgG1， and IgG2a in the C1+P group and C2+P group increased by 8.83， 9.65 times， 13.54， 15.07 times， and 4.27， 5.07 times， respectively. The proportion of CD4⁺ T lymphocytes and CD8⁺ T lymphocytes in the C1+P group and C2+P group increased by 1.15， 1.17 times and 1.11，1.11 times， respectively. The proliferation and activation of spleen cells significantly increased as well （P<0.05）. It is indicated that oral immunization with C1+P and C2+P successfully induced mucosal and systemic immune responses in mice， demonstrating the potential of Chic as a mucosal immune adjuvant and the feasibility of inactivated PEDV vaccines modified with Chic in effectively inducing immune responses.