Method for controlling a hybrid drivetrain which has a drive engine and a dual-clutch gearbox which, to establish two power transmission paths, has a first and a second friction clutch and a first and a second component gearbox. An electric machine is connected to the second power transmission path downstream of the second friction clutch in the power flow direction. Purely electric driving operation can be realized by means of the second component gearbox assigned to the second friction clutch. In the event of a gear change in the second component gearbox during purely electric driving operation, a fill-in torque is provided. The fill-in torque is provided from inertial energy of the previously cranked, non-fired drive engine, wherein the drivetrain also has an electric starter motor, and wherein the starter motor is used to crank the drive engine.