The invention provides a die-casting aluminum workpiece surface cleaning agent. The die-casting aluminum workpiece surface cleaning agent comprises water, phosphoric acid, boric acid, sodium fluoride, 322H, methanol, PH-F and zinc oxide. The cleaning agent has the advantages that the cleaning agent can be applied to acid pickling pretreatment of products, such as aluminum profiles and aluminum alloy, a stronger oil stain and oxide removing function is provided, no corrosion to an aluminum base exists, and the glossness of cleaned products is good. Operations can be performed at room temperature, the energy source is saved, and the acid mist leakage and the waste acid liquid discharge are reduced, so that the damage to the human body and the pollution to the environment are reduced during production link.