Hepatic arterial infusion chemotherapy in conjunction with the combination therapy of atezolizumab (T) and bevacizumab (A) is widely used in hepatocellular carcinoma. Some adverse events such as hypertension, weakness and elevated transaminase levels occurred during treatment, while there is currently no reported case about thrombocytopenia with concomitant HLA antibody-positive PTR. We summarize the critical care nursing experience of a patient with PTR because of HLA antibody positivity during hepatic arterial infusion chemotherapy in conjunction with atezolizumab plus bevacizumab (T + A) regimen. This paper explains the nursing measures for patients with severe thrombocytopenia and proposes nursing measures for situations where conventional treatments are ineffective. Key nursing points include the administration of intravenous immunoglobulin (IVIG) and HLA-compatible platelets, prevention of complications, psychological care, oral care, and skin management. Through systematic treatment and targeted nursing care, the patient's platelet count rebounded after 9 days, leading to a successful recovery and discharge. Subsequent follow-up assessments revealed the patient's sustained well-being. Thrombocytopenia is a potential adverse reaction during the treatment of liver cancer. When platelet transfusion is ineffective, vigilance is necessary for the possibility of HLA positivity, and prompt symptomatic management is warranted.