To compare the immunogenicity of excretory/secretory products of Clonorchis sinensis (CsESP) at different intervals and evaluate their diagnostic value for clonorchiasis. Adult C. sinensis were cultured in vitro, and the culture supernatants collected 0-24 hours and 24-48 hours were mixed to prepare CsESP-1 and CsESP-2 antigens, respectively. Mice were randomly divided into 4 groups: CsESP-1, CsESP-2, adjuvant and PBS groups. Mice in each group were subcutaneously immunized with the corresponding antigen. Blood samples were collected at weeks 0, 2, 4 and 6 post-immunization to prepare immune sera. ELISA was used to measure the antibody titers against CsESP and levels of IgG and IgG1. Additionally, ELISA was employed to detect the levels of CsESP-specific IgG and its subclasses in blood samples from healthy individuals and those infected with C. sinensis. SPSS 27.0 software was used to calculate sensitivity, specificity and Youden’s index. The receiver operating characteristic (ROC) curves and area under the ROC curve (AUC) were computed to evaluate the diagnostic efficacy of the antigens. Blood samples from healthy individuals (Cs^-) and those infected with C. sinensis (Cs⁺), Strongyloides stercoralis, Fasciola gigantica and malaria patients were tested for cross-reactivity using ELISA. Comparisons between two groups were conducted using the t-test, while paired ROC analysis was used for AUC comparisons. ELISA results showed that at week 6 post-immunization, the antibody titers against CsESP in the sera of mice in the CsESP-1 and CsESP-2 groups were 1:102 400 and 1:400, respectively, indicating superior immunogenicity of CsESP-1. At week 6 post-immunization, the A₄₅₀ values for specific IgG and IgG1 in the sera of mice in the CsESP-1 group were 0.926 and 1.803, respectively, both significantly higher than those in the adjuvant group (0.147 and 0.080, respectively) (t = 5.805, 5.643; both P < 0.05). In the CsESP-2 group, the A₄₅₀ values for specific IgG at weeks 2, 4 and 6 post-immunization were 0.279, 0.437 and 0.523, respectively, all higher than those in the adjuvant group (0.133, 0.127, 0.142) (t = 2.906, 5.286, 6.83; P < 0.05, 0.05, 0.01). The A₄₅₀ values for IgG1 in the CsESP-2 group at weeks 4 and 6 post-immunization were 0.225 and 0.332, respectively, both higher than those in the adjuvant group (0.095, 0.083) (t = 3.423, 2.485; both P < 0.05). In Cs⁺ blood samples, the A₄₅₀ values for CsESP-1-specific IgG, IgG2 and IgG4 were 0.817, 0.274 and 0.524, respectively, all higher than those in Cs^- blood samples (0.456, 0.102 and 0.103, respectively) (t = 7.184, 2.720, 5.634; all P < 0.01). For CsESP-2, the A₄₅₀ values in Cs⁺ blood samples for specific IgG, IgG1, IgG2 and IgG4 were 0.783, 0.132, 0.233 and 0.465, respectively, all higher than those in Cs^- blood samples (0.460, 0.068, 0.074 and 0.082, respectively) (t = 4.768, 2.519, 2.634, 4.991; P < 0.01, 0.05, 0.05, 0.01). The CsESP-1 antigen demonstrated the best overall performance in detecting IgG4 in Cs⁺ blood samples, with sensitivity, specificity and accuracy of 89.2%, 86.5% and 87.9%, respectively. Similarly, the CsESP-2 antigen showed the same sensitivity specificity and accuracy (89.2%, 86.5% and 87.9%, respectively) for detecting IgG4 in Cs⁺ samples. ROC curve analysis revealed that the CsESP-1 antigen had moderate diagnostic value for detecting IgG1 and IgG2 (both AUC > 0.7) and high diagnostic value for detecting IgG and IgG4 (both AUC > 0.9). The CsESP-2 antigen exhibited moderate diagnostic value for detecting IgG, IgG1 and IgG2 (all AUC > 0.7) and high diagnostic value for detecting IgG4 (AUC > 0.9). Paired ROC analysis indicated that the diagnostic efficacy of the CsESP-1 antigen for IgG and IgG1 was superior to that of the CsESP-2 antigen (z = 3.515, 2.149; P < 0.01, 0.05). Neither the CsESP-1 nor CsESP-2 antigens showed cross-reactivity with IgG in blood samples from individuals infected with S. stercoralis, F. gigantica or malaria patients. In conclusion, both the CsESP-1 and CsESP-2 antigens prepared in this study exhibited good immunogenicity and could serve as candidate antigens for the diagnosis of clonorchiasis.