The invention discloses ultrahigh-strength steel with a near net shaping function and a preparation method thereof, and belongs to the technical field of manufacturing of ultrahigh-strength steel. Thepreparation method comprises the steps of S1, material preparation; S2, alloy smelting; S3, performance heat treatment, specifically, an alloy ingot obtained in step S2 is placed in a heat treatmentfurnace so as to be subject to performance heat treatment, and according to the specific process of performance heat treatment, heat preservation is conducted for 12-24 h at the temperature of 900-1150 DEGC, then the alloy ingot is cooled to the temperature of 500-750 DEGC with the furnace and then is maintained at the temperature of 5-10 h, and finally, the alloy ingot is air-cooled to the room temperature; and S4, pressure processing of alloy. Compared with similar materials, the ultrahigh-strength steel having the near net shaping function and prepared through the process has the advantagesof excellent mechanical property and near net shaping function.