The invention relates to a cooling system of an electric vehicle lithium battery. The cooling system comprises a lithium battery pack and a water-cooling system, wherein the lithium battery pack comprises single lithium batteries, the water-cooling system is used for integrally cooling the lithium battery pack, the single lithium battery comprises a dual-separator layer, the dual-separator layer is used for isolating a positive electrode and a negative electrode of the single lithium battery, chlorinated paraffin is injected to the dual-separator layer, a hot pipe is inserted into a middle part of the dual-separator layer, a hot pipe of each single lithium battery extends out of one end of the single lithium battery and is connected to the water-cooling system, a phase changing material wraps the periphery of the single lithium battery so as to absorb heat discharged from the single lithium battery, the heat can be stored in a latent heat form, and meanwhile, a heat preservation effectunder a low-temperature environment achieved. By the cooling system, a hot heat region of the lithium battery is enabled to be cooled to the maximum extent, other regions are cooled to a normal extent, so that different regions of an electric vehicle lithium battery obtains different cooling capability effects, meanwhile, the single batteries are preserved, the working of the battery working a cold region is maintained, and the pre-heating link is reduced.