Whilst Hong Kong’s return to Chinese sovereignty in 1997 has influenced education in various ways, major reforms perceived as promoting mainland control have been resisted. For two decades, Hong Kong’s educational autonomy under the ‘one country, two systems’ formula was thus largely maintained. This changed radically with the response to the protests of 2019–2020, culminating in the introduction of a National Security Law. This has drastically constrained Hong Kong’s civil society, enhanced central government control of education and accelerated efforts to reeducate Hongkongers as loyal PRC citizens. We trace how this transformation has been enacted and justified, and reflect on its consequences. We analyse the current situation through the lenses of ‘internal colonialism’ and securitisation, which have characterised governance of China’s restive periphery under Xi Jinping. We argue that analytical perspectives in Comparative Education, relating to postcolonialism/decolonisation and globalisation, obstruct or distort understanding of Hong Kong’s present predicament. 尽管1997年香港回归中国主权已在诸多方面影响其教育，但被视为加强内地控制的主要改革始终被抵制。二十多年来，在“一国两制”方针下，香港的教育自治因此基本得以维持。然而，随着官方对2019-20年公众抗议作出回应，这种情况彻底改变，最终导致2020年《国安法》的出台及一系列相关改革。这些举措已显著限制香港的公民社会，强化中央政府对教育的控制，并加快将香港人再教育为忠诚的中华人民共和国公民的工作。本文追溯这一转变是如何被付诸实际并合法化，同时反思其后果。我们通过“内部殖民主义”和安全化的视角，对当下情况进行分析，这些视角体现了习近平担任主席期间对中国棘手的边缘治理方式的特征。我们认为，比较教育研究中正流行的有关后殖民主义/去殖民化和全球化的分析视角阻碍或扭曲对香港当前困境的理解。