The invention relates to a metal separator, which comprises a hopper, a metal detection channel, a metal detection circuit, an honest material channel, a metal channel and a separation actuating mechanism, wherein, the separation actuating mechanism consists of a baffle, a gas cylinder, an oscillating rod and an electromagnetic gas check. During working, the baffle can be controlled by the separation actuating mechanism to be located at a first work station for closing the entrance of the metal channel, or at a second station for closing the honest material channel; when the metal detection circuit detects that a piece of metal is passing through the metal detection channel, the metal detection circuit supplies electricity to the electromagnetic gas check to actuate the output shaft of the gas cylinder so that the baffle is shifted from the first work station to the second work station; when the metal detection circuit detects that no metal is passing through the metal detection channel, the supply of electricity to the electromagnetic gas check is stopped so that the output shaft of the gas cylinder is returned from the second work station to the first work station. The metal separator of the invention is characterized by long service life, low use cost and maintenance cost.