Objectives To describe the efficacy of convalescent plasma transfusion for COVID-19 patients. Methods Through the review of the electronic medical records of Guizhou Jiangjunshan Hospital, clinical data of 6 patients were obtained. Three of the patients used convalescent plasma therapy for the first treatment, while the other three patients were used during in the recurrence. The efficacy of convalescent plasma depends on the relief of symptoms, changes in laboratory indicators and chest imaging abnormalities. Results The PaO2 / FiO2 and lymphocyte count of patients 1, 2 and 3 treated with convalescent plasma treatment for the first treatment period were changed from abnormal to normal. The levels of inflammation markers CRP and IL-6 of the patients decreased significantly. Chest imaging examination showed that the lung lesions gradually subsided. The relapsed patients (No. 4 and No. 6), after using convalescent plasma therapy, turned negative on two consecutive throat swab tests on Day 24 and Day 3, respectively. The basic condition of patient 4 with in the recurrence was too poor, and only one round of convalescent plasma transfusion was performed, so the laryngeal swab test paper has been consistently positive so far. Conclusions Six patients with COVID-19 were treated with antivirals and systemic corticosteroids combined with appropriate rounds of convalescent plasma therapy, and their clinical conditions were effectively improved.