Chronic graft-versus-host disease (cGVHD) is a clinicopathological syndrome caused by donor lymphocytes attacking the recipient's organs during the process of reestablishing donor immunity after allogeneic hematopoietic stem cell transplantation (allo-HSCT), with an incidence of about 30%-70%. The clinical manifestations of cGVHD are varied, the course of the disease is prolonged, and the quality of life of patients is affected, and the long-term survival is affected. Among them, oral cGVHD is the most common type, which mainly presents with lichen planus, oral ulcers, mucosal atrophy, erythema and pain. At present, the treatment of oral cGVHD is based on systemic treatment and local hormone-containing gargling solution and local photochemotherapy. The former is easy to be complicated by oral local fungal infection, while the latter has no such equipment in China. Therefore, it is urgent to establish a simple, effective and low-toxicity local treatment for oral cGVHD. Mesenchymal stem cells (MSCs) are one of the most widely used cell products in clinic. The combination of MSCS and hematopoietic stem cells can improve the success rate of transplantation and accelerate hematopoietic reconstruction. The applicant team previously completed a national multi-center clinical study on MSCs prevention of cGVHD, which proved that sequential infusion of MSCs can effectively reduce the incidence of cGVHD, and the mechanism is that MSCs regulate Th1: Th2 balance and promote the differentiation of T cells to Th1 direction. Our previous mechanism study provides an important theoretical basis for MSCs treatment of oral cGVHD. According to the clinical needs and the rich experience of our research group in the field of MSCs clinical research, we plan to use dressing containing MSCs for the local treatment of oral cGVHD, so as to improve the lesion degree of oral cGVHD and improve the quality of life of allo-HSCT patients, and provide clinical experience for reference for the local treatment of MSCs graft-versus-host disease.