A method and an apparatus for controlling a mild hybrid electric vehicle are provided. The method includes detecting data for operating the vehicle and determining a target torque of an engine based on the detected data. Additionally, the method includes determining whether an operating condition of a limiting logic of a combustion torque of the engine is satisfied based on a temperature of coolant of the engine and operating the limiting logic when the operating condition of the limiting logic is satisfied. A first available combustion torque of the engine is determined based on a speed of the engine and the temperature of the coolant when the limiting logic is operated and a target torque of a MHSG is determined based on the target torque of the engine and the first available combustion torque of the engine. The MHSG is then operated to generate the target torque of the MHSG.