The impact of international tourism on biodiversity risks has received considerable attention, yet quantitative research in this field remains relatively limited. This study constructs a biodiversity risk index for 155 countries and regions spanning the years 2001 to 2019, analysing how international tourism influences biodiversity risks in destination countries. The results indicate that the growth of international tourism significantly elevates biodiversity risks, with these effects displaying both lagging and cumulative characteristics. Furthermore, spatial analysis shows that international tourism also intensifies biodiversity risks in neighbouring countries. The extent of its impact varies according to the tourism model and destination. In addition, government regulations and international financial assistance play a crucial role in mitigating the biodiversity risks associated with international tourism.