Disclosed is an electric power conversion control device, in which when an overvoltage abnormality of an electric power system is detected, and it is detected that a vehicle is not in collision, a switching control unit stops the switching of an inverter, whereby an element of the inverter is prevented from being subjected to an overvoltage. In a case where an overvoltage abnormality of the electric power system is detected, and when it is detected that the vehicle is in collision, the switching control unit performs the switching of the inverter, whereby electrical energy of the electric power system is rapidly consumed by a motor generator. Accordingly, it is possible to properly control the switching of an electric converter depending on whether an overvoltage abnormality occurs and a vehicle is in collision.