A method for removing phosphorus includes at least the steps of: 1) placing lanthanum oxide hydrate (absorbent) into a device for removing phosphorus, and allowing sewage having a phosphorus content of less than 100 mg/L to flow through the device; 2) adding sodium hydroxide (regeneration solution of the absorbent) when the absorption capacity of the device is exhausted, and allowing the regeneration reaction to proceed for between 4 and 12 hours; and 3) collecting eluate from step 2) and recycling phosphorus.