A method for controlling a hybrid power unit with power bypass for an automobile including at least two driving wheels, wherein the power unit includes a thermal engine, at least two electric machines, and an infinitely variable transmission mechanically connecting the thermal engine, the two electric machines, and the driving wheels. In the method, an initially stopped thermal engine is brought, in an independent manner and in plural operation phases, to a rotation speed that is sufficient for participating in propulsion of the vehicle, the vehicle moving under action of the electric machines.