The invention provides a processing method for a circuit board. The processing method comprises the following steps: performing pyrolysis on the circuit board to obtain a pyrolysis flue gas and solidresidues; and taking the pyrolysis gas as part of a fuel in a side-blown smelting process of heavy metal sludge to perform side-blown smelting on the heavy metal sludge. The pyrolysis gas produced bypyrolysis of the circuit board is high in temperature, contains many organics, and therefore, has a high calorific value. Further, when the pyrolysis process of the circuit board and side-blown smelting of the heavy metal sludge are combined, the pyrolysis gas serves as part of the fuel in the side-blown smelting process of the heavy metal sludge, and further, the calorific value of the part is fully utilized. Meanwhile, environmental pollution caused by discharge of the organics is avoided, and the side-blown smelting cost of the heavy metal sludge is lowered. In the side-blown smelting technological process, through sufficient combustion under an oxygen-rich condition, the pollution degree of a smelting gas is low.