A method prevents the stalling of the engine of a hybrid vehicle (1) equipped with an auxiliary motor (4) and wheels (R1 to R4), pistons (2a to 2d), tank (3), axle (5), drive shaft (6), gearbox (7), connections (8a, 8b), and computer (9). The method uses an estimate of the predicted instantaneous speed of the main engine (2) at its next top dead center, for the purpose of assisting the main engine in a stall situation, via the auxiliary motor which can supply sufficient power to it on a one-off basis to prevent it from stopping. The method defines two levels of instantaneous speed. If the predicted instantaneous speed is located in the intervention zone between the two levels, the auxiliary motor assists the rotation of the main engine to enable it to rotate in the same direction, without stalling.