Risk assessment of alien plants is the most economical and effective measure to prevent the invasion of alien species, and it can greatly save the economic and time cost of alien species management. In this paper, the risk assessment system of alien plants in China and abroad is briefly introduced. The existing problems in the risk assessment of alien plants in China are expounded on the lacking of the basic information of alien plants, incomplete suitable area analysis, unobjective construction process of risk assessment system, and insufficient attention to risk analysis of newly alien plants. The following suggestions are given for the existing problems. (1) Establishment of the basic information database of alien plants is the basis of risk assessment. In order to provide evidence for risk assessment, the investigation and textual research of background data of alien plants should be strengthened, and the accumulation and analysis of phenotypic data of alien plants should be added into the database, which helps to improve the management of alien species. (2) The application of ecological niche model to ecological risk analysis is the important part of risk assessment, and human activity indicators should be considered in the niche model to reveal its impact on the distribution pattern of invasive plants. The transfer ability of the model should be fully considered when selecting geographical distribution data and environmental variables for model construction. The accuracy and reliability of the model are evaluated and the optimal model is selected according to the assessment result. (3) The scientificity is the core of risk assessment system. The measures to improve the scientificity of risk assessment system include selecting the risk index and setting weight, establishment of the risk assessment system for particular area or specific ecological types, establishment of evaluation standards in line with the actual requirements according to the biological and ecological characteristics. (4) Strengthening the management of newly alien plants is the key part. The population dynamics of newly alien species should be monitored regularly. At the same time, the results of risk assessment should be reviewed regularly, and the high-risk newly alien species should be warned. The early stage is the best time to manage alien species. Risk assessment and early warning of alien species that have not caused significant harm can reduce the cost of prevention and control.This study will provide an important reference for the establishment of risk assessment system for alien plants in China and provide a theoretical basis for the formulation of invasive plant prevention and control measures.