The utility model relates to the technical field of road construction, in particular to a forming device of a fence plate for road construction, which comprises a rack, a lower male die, a pressing and rolling mechanism, a chain transmission mechanism, a connecting piece and a speed reducing motor, the plurality of lower male dies are fixedly arranged on the rack at intervals; the pressing and rolling mechanism comprises a sliding support and a plurality of pressing and rolling units corresponding to the lower male dies. The pressing roller unit comprises a pressing roller bracket, a middle roller, a side roller, a vertical spring, a left spring and a right spring; the vertical spring is used for generating a vertically downward acting force on the pressing roller bracket; the side rollersare located on two sides of the middle roller; the left and right springs are used for generating acting force towards the middle roller; a groove formed by the middle roller and the side rollers ismatched with the lower male die; and the chain transmission mechanism can drive the sliding bracket to reciprocate back and forth through the connecting piece during one-way transmission. The formingdevice of the fence plate for road construction is low in cost, small in occupied space and easy to maintain, the influence on the workshop environment can be reduced, automatic adjustment can be achieved according to the thickness of a plate blank, and the size precision of the machined fence plate for road construction is high.