The invention relates to a copper-plating method of magnesium alloy wires, in particular to a copper-plating method of MB2 magnesium alloy wires, which is used for solving the technical problems such as complex process and high possibility of forming bulges and burrs on plating layers in the existing copper-plating method of magnesium alloy wires by utilizing a zinc dipping process. The copper-plating method comprises the following steps: grinding the MB2 magnesium alloy wires by utilizing abrasive paper; ultrasonically cleaning the ground MB2 magnesium alloy wires; de-oiling; acid cleaning; placing the cleaned MB2 magnesium alloy wires in zinc dipping solution for treating at the temperature of 70-90 DEG C for 20-30 minutes to obtain zinc-plated MB2 magnesium alloy wires; and placing thezinc-plated MB2 magnesium alloy wires in electroplating solution for electroplating at the temperature of 35-45 DEG C and current density of 1-2A/dm<2> for 30-40 minutes to finally obtain the copper-plated MB2 magnesium alloy wires. By utilizing the copper-plating method, pre-plating procedures are simplified and the formed plating layers are uniform and compact; and the obtained copper-plated MB2 magnesium alloy wires can be applied to the fields such as electronics, electrical appliances, vehicles, aerospace and civil products.