In one embodiment, a method of over voltage protection control can include: (i) determining whether an output voltage of a buck-boost converter is in an over voltage condition, where the buck-boost converter includes a first switch coupled to an input terminal and an inductor, a second switch coupled to ground and a common node of the first switch and the inductor, a third switch coupled to ground and a common node of a fourth switch and the inductor, where the fourth switch is coupled to an output terminal of the buck-boost converter; and (ii) simultaneously controlling the first, second, third, and fourth switches in the buck-boost converter by turning on the second and third switches, and turning off the first and fourth switches, in response to the over voltage condition.