The global market for lithium-ion batteries continues to grow, and the number of spent lithium-ion batteries is increasing along with the wave of battery retirements. As an important secondary resource, the recycling of spent lithium-ion batteries is of great significance in alleviating the consumption of battery raw materials and avoiding environmental pollution. In the recycling process, the separation of the cathode active material containing valuable metals from the collector is an important prerequisite for reducing the difficulty and complexity of the subsequent metal extraction process. Unlike most reviews that focus on metal extraction, this paper discusses and analyses the separation techniques of cathode active material. Starting from the bonding mechanism between cathode active material and collector, the separation techniques (mechanical, dissolution, pyrolysis and other novel methods) are discussed in detail. The dissociation mechanisms involved in the separation technology are discussed in focus, and an outlook on the subsequent separation technology for cathode materials is presented. This paper helps to provide a systematic understanding for researchers and workers interested in the separation of electrode materials from spent lithium-ion batteries, and has important reference value.