UNESCO's relatively high prestige across East Asia has spurred intensifying efforts by governments to use its imprimatur to legitimate official narratives of the past and visions of the future. This article focuses on China's use of UNESCO as an arena for competitive national 'branding' in the education field, especially relating to STEM and AI. We analyse the Chinese state's engagement with UNESCO's education work in the context of shifts in budgetary and political influence within the organisation, and of a growing 'securitisation' of education within China itself. We show how Chinese engagement with UNESCO's educational agenda reflects both domestic political considerations and the 'major country diplomacy' of Xi Jinping, as manifested in the 'Belt and Road Initiative' and intensifying strategic competition with the USA. We conclude by discussing the implications of rising Chinese influence within the organisation for UNESCO's capacity for articulating a coherent and consistently humanistic vision for education.