Disclosed is a method for controlling a drive train (1) of a motor vehicle, especially an off-road vehicle, comprising a drive engine (2), a multi-group transmission (4), an output and a control device. The multi-group transmission (4) consists of at least one automatic gearbox (8) and a downstream range-change unit (9). When a modification occurs in the multiplication of the range-change unit (9), a) the drive train is relieved by modifying the torque of the drive engine (2), a shift element (24, 25) to be switched off in said range-change unit (9) is disconnected, c) a shift element (24,25) to be switched on in said range-change unit is synchronized and switched on and d) a multiplication of the automatic gearbox (8) is modified in such a way that the modification of the multiplication of the multi-group transmission (4) is smaller than a single modification of the multiplication of the range-change unit (9). A rotational speed of the drive engine (2) is adjusted by a modification in the transmissibility of at least one shift element of the automatic gearbox (8) to a coupling rotational speed equivalent to the adjusting multiplication of the multi-group transmission (4) at which the shift element to be switched on in the range-change unit (9) is synchronous.