DRG payment reform is an important means to control the unreasonable growth of medical expenses, improve the quality of medical services and achieve a win-win situation among three sides of hospitals, medical insurance and patients. This study adopted the Smith policy implementation process model to analyze the difficulties in the DRG policy implementation process from four aspects(idealized policies, policy implementation institutions, target groups, and policy environment), including the deviation between policy connotations and actual needs; the interest objectives of all parties were not completely aligned, the target group lacked a sense of identity, and the social impact and technological support needed to be improved. It was suggested that optimization should be carried out from four dimensions: policy supply coordination and precision, performance evaluation and personnel literacy, target group cognitive level and participation willingness, and policy implementation environment and atmosphere, in order to synergistically promote the effective implementation of DRG policies.