Objective To analyze the rehospitalization rate and influencing factors of patients with bipolar depressive episode after effective treatment in acute phase for 3 years. Methods A total of 315 patients with bipolar depression during acute phase， who were hospitalized and received effective treatment in Beijing Anding Hospital of Capital Medical University from September 2015 to September 2018， were recruited as research objects by convenience sampling method. Demographic information， medical history， clinical features and other data of patients were collected. The patients were followed up for 3 years， and their rehospitalization conditions were tracked. The Cox proportional risk model was used to analyze the influencing factors of rehospitalization of patients with bipolar depressive episode after effective treatment in acute phase for 3 years. Results A total of 289 patients completed follow-up， and 39.45% （114/289） of them were readmitted to hospital within 3 years. Multivariate Cox regression analysis showed that the total number of attacks was a risk factor for readmission 3 years after treatment （HR=1.081， 95%CI：1.040-1.124，P＜ 0.01）， and the baseline treatment of mood stabilizers/antipsychotic was a protective factor for readmission 3 years after treatment （HR=0.471， 95%CI： 0.321-0.692， P ＜ 0.01）. Conclusions Multiple episodes， mood stabilizers/antipsychotics combined with antidepressant in the acute phase are the risk factors for patients with bipolar disorder to be readmitted within 3 years after effective treatment in the acute phase. Clinical attention should be paid enough and corresponding intervention should be carried out.