Disclosed in the invention is a plastic-based composite material capable of conducting electricity and shielding electromagnetic wave. The plastic-based composite material is prepared from the following raw materials in parts by mass: 40 to 80 parts of plastic matrix, 5 to 15 parts of surface modified high-efficiency conductive agent, 10 to 40 parts of ferroferric oxide, 5 to 10 parts of compatibilizer, and 0.5 to 1 part of antioxidant. The product has good conductive property and mechanical properties, can shield the electromagnetic wave in a high degree, and can be widely applied to the fields of electronic consumer goods, remote monitoring/communication, military, and field/indoor power supply.