An oxidized β-1,4-oligoglucuronic acid, and a preparation method therefor and uses thereof. By using abundant cellulose in the natural world as the raw material, all 6-site hydroxyl groups of the cellulose β-1,4-polyglucose is oxidized into carboxyl groups to form glucuronic acid under the action of a sodium bromide (NaBr)-2,2,6,6-tetramethyl piperidine oxide (TEMPO)-sodium hypochlorite (NaClO) oxidation system, and the oxidized oligoglucuronic acid having an open ring at an end is prepared by controlling reaction conditions. The compound has obvious anti-cerebral ischemia activity, and can be developed into a potential anti-cerebral ischemia drug.