The most common side effect of MSC injection is hypothermia or moderate fever, but the body temperature rarely exceeds 38℃. At the same time, a small number of patients also have mild headache after injection, some of them have nausea and vomiting, usually these symptoms can be recovered after half a day or so, and can be treated with dexamethasone or anti-inflammatory painkillers. In addition, a small number of patients will have facial flushing after MSC injection, but it will disappear gradually in about 2 hours. Therefore, the side effects of MSCs are relatively rare and mild, which are easy to deal with. At present, MSCs are mainly used as adjuvant therapy for hematopoietic stem cell transplantation, and the injection of MSCs can promote the recovery of hematopoietic stem cell transplantation to the patient’s hematopoietic function as soon as possible.