Spent lithium-ion batteries have the dual properties of mineral resources and environmental pollution, they are not only rich in key metals with high external dependence in China, but also contain toxic and harmful substances such as heavy metals and organic pollutants. Efficient recycling of spent lithium-ion batteries is the key to ensure the sustainable development of strategic emerging industries such as electric vehicles. Lithium-ion batteries have various categories associated with complex structures and different organic compounds. Conventional pyrometallurgical and hydrometallurgical processes are likely to produce secondary environmental hazards, which affects the subsequent efficient recycling of metals. Heat treatment has attracted extensive attention in the industry in recent years, since it helps effective recovery of valuable metal resources. Heat treatment technology enjoys many advantages, such as little secondary pollution, attainable equipment, readily scaling up and low costs. Associated with the heat treatment method, the pollution control at the very beginning of recycling spent lithium-ion batteries can not only realize clean production, but also strengthen the subsequent in-depth treatment. Based on the current situation and strategic needs of the industry, this work focused on the generation, migration and transformation of pollutants in the pretreatment of spent lithium-ion batteries. The technical advantages of heat treatment were compared and summarized in the aspects of impurity removal and pollution prevention and control. Meanwhile, the heat treatment processes of spent lithium-ion batteries were systematically classified, and the material transformation mechanism under different heat treatment conditions was summarized.