The invention discloses a steel bar derusting device, which comprises a base, a support column is fixedly connected to both sides of the top of the base, a box body is fixedly connected to the top of the support column, long holes are opened on both sides of the box body, and the top of the box body is fixed. A liquid storage tank is connected, and a water pump is arranged in the inner chamber of the liquid storage tank, and the water inlet pipe of the water pump runs through the liquid storage tank and extends to the left side of the liquid storage tank. The steel bar derusting device, through the box, the water pump, the hose, the standpipe, the shunt pipe, the nozzle, the electric telescopic rod, the first motor, the first rotating rod, the first wire brush, the second motor, the second rotating rod, The combined use of the second steel wire brush, casing, spring, bracket and grinding wheel has the advantages of efficient rust removal, and solves the problem that the existing steel bar rust removal device has a relatively single structure, and most of the steel bars are derusted by grinding, and cannot be rusted according to The size of the steel bar is fixed and cleaned, which not only increases the workload of the user but also reduces the practicality of the derusting device.