Provided are a charger and a control method. The charger includes: a transformer; at least one primary-side switch tube for carrying out chopping modulation on a voltage input into the transformer; a first control unit; a second control unit for generating feedback information on the basis of a voltage and/or current information output from an output end of the charger; and a first microwave unit respectively connected to the first control unit and the second control unit, and used for transmitting the feedback information to the first control unit. The first control unit is used for outputting a first control signal according to the feedback information, so as to control the turning on or the turning off of the at least one primary-side switch tube.