Over the past decade, China has significantly expanded its security cooperation with other authoritarian regimes, yet existing research struggles to capture the informal and ambiguous nature of these relationships. This article develops a new conceptualisation of ‘security ties’ grounded in the logic of authoritarian rule. Security ties are sustained interactions that contribute to regime survival and unfold across five functional domains: diplomatic and military contacts, support for regime security, military capacity building, non-combat operations, and wartime support. To capture variation, this article analyses security ties along three dimensions: depth, durability, and domestic involvement. As a proof of concept, the framework is applied to China’s security ties with ten representatively selected autocracies between 2019 and 2024. The analysis reveals that China’s ties to Russia are by far the deepest, most durable, and institutionalised. Ties to other autocracies are more selective and uneven. Military capacity building emerges as a central but varied pillar, while cooperation aimed at regime security and wartime support remains limited to a narrow set of partners. The article advances debates on authoritarian alignment by conceptualising it as a differentiated web of security ties rather than a cohesive alliance, and it offers a framework for systematically analysing autocratic security cooperation.