The invention discloses a size-graded steel fiber elevating concrete which is prepared from the following raw materials in parts by mass: 176-182 parts of water, 460-470 parts of cement, 70-80 parts of fly ash, 48-55 parts of expanding agent, 900-915 parts of river sand, 605-625 parts of macadam, 9.85-10.45 parts of polycarboxylic-acid water reducing agent and 130-140 parts of steel fiber. The steel fibers have three particle sizes, 30mm, 25mm and 13mm; and the mass ratio 30mm:25mm:13mm is 1:0.31:0.31. The preparation method comprises the following steps: adding the steel fibers by five timesto be mixed with the river sand and macadam, sequentially and proportionally adding the cement, fly ash and expanding agent into a mixer, and carrying out dry mixing for 80-100 seconds; and adding the mixture of the water and polycarboxylic-acid water reducing agent into the mixer, evenly mixing for 180 seconds, and discharging. The size-graded steel fiber concrete overcomes the defects of poor working properties and mechanical properties in the single steel fiber concrete, and has better uniformity, workability and crack resistance than common steel fiber concrete.