[Aim] We developed an ecological risk assessment system for exotic garden plants, promoting effective judgment, beneficial usage, and differentiated management and control of these species. We used this system in the early construction of the national wetland park and provided references for future development of other ecological wetland parks. [Method] A comprehensive survey was conducted on the plant species composition and current situation of exotic plant invasion in South Dianchi National Wetland Park. Through literature research and expert consultation, an ecological risk evaluation system for exotic garden plants in South Dianchi National Wetland Park was developed. The index weight was determined using the analytic hierarchy process, plant risk value was determined after the evaluation, risk level was divided, and management and control suggestions were proposed. [Result] (1) The evaluation system established 3 primary indicators with weights of 70%, 10% and 20%. (2) There were 188 species of plants in South Dianchi National Wetland Park, of which 57 species were exotic, accounting for 30.3% of all plant species in the park; 8, 20, and 29 species were high-, medium-, and low-risk plants, respectively, accounting for 14.0%, 35.1%, and 50.9% of the total number of exotic garden plants, respectively. [Conclusion] Exotic garden plants in South Dianchi National Wetland Park are diverse and extensive, with varying degrees of harm. Phased removal is recommended, and high-risk plants should be replaced with native plants. Enhanced control and long-term intensive monitoring are recommended for medium-risk plants. For low-risk plants, it is suggested to retain the primary ecological niche and conduct monitoring and management.