[Aim] Salvinia molesta D. S. Mitchell is a perennial, free-floating aquatic plant native to southeastern Brazil. It has been widely introduced and has escaped into the wild worldwide, invading various aquatic habitats, including lakes, rivers, and rice paddies. Assessing invasive risks and formulating management measures may provide the scientific basis for quarantine decision-making and prevention.[Methods] In this study, by searching and classifying relevant literature, we qualitatively analyzed the domestic and foreign distribution, means of movement and dispersal, invasion and spread history, control methods, ecological adaptability and stress resistance, biological and genetic characteristics, hazard and utilization values of S. molesta. Based on the alien plant risk index system and assignment criteria, 17 indices and 32 questions in four index layers were assigned to quantitatively analyze the risk of S. molesta invasion.[Results] We observed that S. molesta has invaded 57 countries and regions through natural and human movement. It undergoes rapid vegetative reproduction through growth and fragmentation to establish populations. S. molesta has strong ecological adaptability, stress resistance, and competitiveness, making quarantine identification and eradication difficult. Thus, it has a significant negative impact on the economy, ecology, and society. The invasibility (R₁), adaptability (R₂), diffusivity (R₃), and harmfulness (R₄) values were 72, 53, 82, and 81, respectively. The risk value for S. molesta was 73.4, indicating that it should be classified as a plant that is strictly prohibited from being introduced.[Conclusions] Despite its limited distribution range in China, S. molesta has a high invasive risk, and the possibility of escape, spread, and harm cannot be ignored. Its introduction is strictly prohibited. Considering that this species has been introduced into China and has market demand as an ornamental plant, a corresponding risk management system should be formulated for the regular implementation of quarantine, monitoring, and eradication activities, to prevent it from escaping to the wild and colonizing and spreading to pest-free areas.