A method and apparatus for controlling part load mode engine torque are provided. The method includes setting a limitation of part load mode engine torque based on a current traveling environment and calculating a first engine torque variation in the basis of state information of a battery. When the first engine torque variation is calculated, a second engine torque variation is calculated based on a measured engine error amount. The limitation of part load mode engine torque is compensated based on the calculated first and second engine torque variations.