A current collector, an electrode plate, and an electrochemical device are provided in the present disclosure. The current collector includes an insulation layer and at least one conductive layer. The insulation layer is used to support the conductive layer. The at least one conductive layer is used to support an electrode active material layer and is located above at least one surface of the insulation layer. The insulation layer has a density smaller than that of the conductive layer. A metal protective layer is arranged on at least one surface of each of the at least one conductive layer.