Provided is a backflow cascade novel process for producing a lithium-7 isotope. The process comprises an upper backflow section, an extraction section, an enrichment section, a lower backflow section, and a product acquiring section. Upper backflow phase-conversion liquid and lower backflow phase-conversion liquid are respectively added to the upper backflow section and the lower backflow section, and upper backflow phase-conversion liquid and lower backflow phase-conversion liquid of the lithium material are controlled; the product is precisely acquired in the product acquiring section; an organic phase is added to the upper backflow section, and is recycled in the lower backflow section. By means of cascade connection with a high-performance liquid separator, environmental protection, high efficiency, and multi-level enrichment of the lithium-7 isotope are achieved, and a high-abundance lithium-7 isotope product is obtained.