Objective To analyze the correlation between B lymphocyte stimulating factor (BLyS) and its receptor B lymphocyte stimulating factor receptor (AFF-R) and serum immunological indexes in patients with chronic immune thrombocytopenia (ITP). Methods Fifty cases of ITP patients admitted to the hematology department of our hospital from January 2020 to January 2022 were selected as the observation group for retrospective study, and 50 cases of healthy physical examination patients admitted to the physical examination center of our hospital during the same period were selected as the control group. Serum BLyS, AFF-R and immunological indexes of the two groups were detected and compared. Serum BLyS, AFF-R and immunological indexes were compared in different severity groups. All ITP patients were given symptomatic treatment such as dexamethasone, gamma globulin and prednisone. Serum BLyS, AFF-R and immunological indexes were compared between the poor prognosis group and the good prognosis group. The correlation between BLyS, AFF-R and immunological indexes was analyzed by Pearson, receiver operating curve (ROC) was drawn, and area under the curve (AUC) was calculated. To analyze the predictive efficacy of BLyS, AFF-R and immunological indexes for poor prognosis in patients with ITP. Results Serum BLyS, AFF-R, peripheral blood IgG, IgA and IgM in observation group were higher than those in control group (P＜0.05). Serum BLyS, AFF-R, peripheral blood IgG, IgA and IgM in severe group were higher than those in moderate and mild groups (P＜0.05). Serum BLyS, AFF-R, peripheral blood IgG, IgA and IgM in poor prognosis group were higher than those in good prognosis group (P＜0.05). BLyS, AFF-R were positively correlated with IgG, IgA and IgM (P＜0.05) (r=4.034, 3.986, 4.134, 3.964, 4.006, 4.086). The AUC of BLyS, AFF-R, IgG, IgA and IgM in predicting poor prognosis of ITP was 0.801 (95%CI:0.734-0.959), and the sensitivity and specificity were 93.62% and 90.24%, respectively, higher than that of single detection (P＜0.05).Conclusion The expression levels of BLyS and its receptor AFF-R in ITP patients will gradually increase with the aggravation of the disease, and are positively correlated with serum immunological indexes IgG, IgA and IgM. Combined detection can improve the sensitivity and specificity of predicting poor prognosis, which has certain reference value