Studying the impact of different degrees of invasive alien plants on regional community structure and plant species diversity is of great significance for evaluating their harm to ecosystems. Xanthium italicum is an invasive weed that is widely distributed in world. Its adaptability and competitive advantage over native species have led to agricultural loss and biodiversity reduction, yet its impact on local plant communities under different degrees of invasion has not been reported. In this study, we select the X. italicum as the main research object, the Midong District of Urumqi City, Xinjiang, China was selected as the research area for plant sampling investigation, which has obvious X. italicum hazards and a large distribution area. From the perspective of X. italicum and its symbiotic local plants, this study explored the changes in species diversity and community stability of local plant communities under different levels of invasion, using species diversity index, community stability, community invasibility, impact degree index, competitive advantage of invasive plants, and invasion intensity. The results showed that: (1) Compared with the uninvasive areas, the mild invasion of X. italicum significantly increased the species diversity of local plant communities (P ＜ 0.05), while severe invasion significantly reduced the species diversity of local plant communities (P ＜ 0.05). (2) In communities invaded by X. italicum, community stability decreased by 25% from low to heavy invasion levels, while the invasibility, competitive advantage index, and invasion intensity index of X. italicum increased by 77%, 79%, and 83%, respectively. (3) At a low invasion level, the impact index of X. italicum on species diversity, community stability, and community species number of this plant community was ＜ 0, which had positive impact. Conversely, the impact index of X. italicum under low to moderate and heavy invasion levels on species diversity, community stability, and community species number of the plant community was ＞ 0, which resulted in negative impacts. (4) The diversity and stability of local plant communities were positively correlated, but negatively correlated with community invasibility (P ＜ 0.05). (5) The Shannon-Wiener index had the highest direct pathway coefficient (0.828) for community stability, whereas the Simpson's index had the highest direct pathway coefficient (0.932) for community invasibility. Our results show that moderate and heavy invasion by X. italicum has a huge impact on the structure of plant communities in Xinjiang, in addition to immeasurable impacts on the fragile ecosystem and indigenous species diversity of this area. We propose that X. italicum should be controlled and eradicated in the early stages of invasion to prevent irreversible and severe damage to plant communities in Xinjiang, as the core and hub of the "Belt and Road."