Exciting current control circuit and control method

The invention discloses an exciting current control circuit and a control method. The exciting current control circuit comprises a relay, a mainboard control circuit and an absorption circuit, a current output port of the absorption circuit is connected with a first port of the relay; a current input port of the absorption circuit is connected with a second port of the relay; and a first port and a second port of the relay are respectively connected to the mainboard control circuit. The excitation current generated at the moment when the transformer of the unit is powered on is restrained, so that unit air switch tripping caused by large excitation current is avoided, impact of large current on upstream and downstream parts is reduced, and normal operation of the unit is guaranteed.