The invention discloses a high-efficiency grinding and derusting equipment for steel bars for construction, which comprises a bottom plate, a left side plate, a right side plate, a top plate, a slide rail, a first slider, a box body, a first spring, a workbench, a sleeve, a slide Rod, mounting plate, first motor, first clamping device, second clamping device, horizontal support plate, second motor, disc, connecting rod, second slider, rack, third slider, pull cord , the first fixed pulley, the second fixed pulley, racks, gears, rotating shafts, and grinding discs. The present invention is provided with a first clamping device and a second clamping device, which can fix steel bars of different diameters. The first motor, the second motor, the disc, the second slider, the rack, the gear, the third slider, the pull rope, the box body and the spring, through the cooperation of the above components, the steel bar can be polished in all directions, which further improves the grinding efficiency , with a first helical gear, a second helical gear and a threaded rod to adjust the distance between the workbench and the grinding disc to accommodate steel bars of different diameters.