Capillary multistage interface enrichment system and separation and enrichment method for lithium isotopes

The invention discloses a lithium isotope capillary multistage interface enrichment system and a lithium isotope separation and enrichment method. The capillary multistage interface enrichment system comprises a lithium salt aqueous solution, a non-lithium salt aqueous solution and more than one capillary, two ends of the capillary are respectively arranged in the lithium salt aqueous solution and the non-lithium salt aqueous solution, and a plurality of organic phase solutions and aqueous phase solutions are alternately arranged in the capillary. A plurality of liquid-liquid interfaces are formed between the organic phase solution and the aqueous phase solution, and a section of solution, close to the lithium salt aqueous solution, in the capillary tube is the organic phase solution; plugging objects are arranged at the two ends of the capillary tube, and lithium ions can pass through the plugging objects. According to the lithium isotope capillary multistage interface enrichment system provided by the inven