The invention discloses a method of extraction separation of yttrium (Y) and belongs to the technical field of rare earth metal extraction. The method particularly includes the steps of: (1) extracting a crude Y solution with a saponified organic phase so that the organic phase supports the Y, and separating a YHoErTmYbLu chloride solution with the organic phase supporting the Y and a low-Y heavy rare earth chloride solution, thereby obtaining a crude Y water phase containing Ca and an organic phase supporting low-Y heavy rare earth; (2) extracting the crude Y solution through the saponified organic phase so that the organic phase supports the Y, and separating the Ca in the organic phase supporting Y with a YCl3 solution to prepare a crude Y water phase containing Ca and a Y organic phase; (3) separating the organic phase of the low-Y heavy rare earth with the Y organic phase and a (HoErTmYbLu)Cl3 solution to obtain a pure Y water phase and a HoErTmYbLu organic phase; and (4) feeding a part of the pure Y water phase to the step (2) through an inter-stage series pipeline, while the rest of the Y water phase is a product. The method is used for separating Y from rare earth, is low in raw material feeding cost and separation cost and is less in generated production wastewater.