A method for operating a drive train of a hybrid vehicle with a hybrid drive comprising at least an electric machine and an internal combustion engine, wherein an automated manual transmission is connected between the internal combustion engine and an output, wherein the electric machine is coupled via a friction clutch to a shaft of the automated manual transmission. Wherein in the automated manual transmission, by interruption of the drive torque provided by the hybrid drive on the output, shifts are executed in such a way that in a first phase the drive torque provided at the output is first reduced, subsequently in a second phase the actual gear shift is executed and following that in a third phase drive torque is built up at the output. Wherein for execution of the actual shift after a gear disengagement of an actual gear of the shift and before a gear engagement of a target gear of the shift, the automated manual transmission is synchronized using a flywheel mass of the electric machine such that, when the friction clutch is opened, the rotational speed of the electric machine is brought to an inertial rotational speed and that subsequently the friction clutch is first closed to the inertial synchronization of the manual transmission and subsequently at least partially opened again.