A power train control device includes a requested torque calculation unit that calculates requested torque for an engine based on a parameter input from an upper level computing device, a transmission gear ratio determination unit that determines a transmission gear ratio, a transmission control unit that calculates output shaft torque and gearshift time of an automatic transmission at the time of gearshift and outputs a control parameter to an automatic transmission control device, a generated driving torque calculation unit that calculates driving torque generated in the power train, taking account of the load torque of the engine input from a load torque computing device, and outputs the calculated driving torque to the upper level computing device, and an availability calculation unit that calculates and outputs availability of the driving torque to the upper level computing device.