Disclosed a conversion device for a quick charger, comprising an input end, a voltage regulator module, a recognition module, a control module and an output end, wherein, the voltage regulator module receives a power voltage through the input end to stabilize a voltage, and outputs the power voltage after voltage stabilization to the recognition module and the control module; the control module reads a conversion voltage of the output end, and produces a conversion signal group according to the conversion voltage to output to the recognition module; and the recognition module produces a handshake signal and a voltage recognition signal according to the conversion signal, and outputs through the input end. Through the device and method, equipment that are not quickly charged may also be charged by the quick charger, so that an application scope of the quick charger is expanded.