Fossil fuel combustion, automobile exhaust emissions, metallurgical industry emissions, mining and other human activities have discharged a large amount of heavy metals into the atmosphere, resulting in increasingly serious heavy metal pollution, which seriously threatens the environmental quality of soil and water and plant safety. Heavy metals in the atmosphere will participate in the biochemical cycle of plant system after dry and wet deposition. Different from the widely studied absorption of heavy metals by roots, scholars have little knowledge about the mechanism of heavy metal absorption by plant leaves and the resulting effects. If we can deeply study the absorption and transport mechanism of heavy metals in plant leaves, verify the toxicity of heavy metals to plants and the detoxification of plants, we can provide new ideas for plant leaves to resist heavy metal pollution and ensure the safety of plants and related products. In this paper, the previous work was summarized, the mechanism of heavy metal absorption and transport by plant leaves was systematically reviewed, and the morphological changes of heavy metals in leaves, the toxicity of heavy metals and the detoxification of plants were analyzed.