A steering control device comprising: a steering input mechanism (St IN) in which an input shaft is rotated by a steering operation by a driver; a turning output mechanism (St OUT) configured to turn a wheel by a rotation of an output shaft; a clutch configured to couple the input shaft and the output shaft such that the input shaft and the output shaft are couplable and decouplable; a first motor capable of providing driving force to the turning output mechanism (St OUT); a second motor capable of providing driving force to the turning output mechanism (St OUT); a first control unit configured to control driving of the first motor; a second control unit configured to control driving of the second motor; and a torque detection unit configured to detect a torque of the output shaft, wherein at least the first motor and the torque detection unit are configured as an integrated composite component, characterized in that the second control unit is configured to perform a one-motor turning control mode when at least one of the first control unit, the first motor, and the torque detection unit malfunctions, in a state where the first control unit and the second control unit perform a two-motor turning control mode, the first control unit is configured to perform a one-motor assist control mode even in a state the one-motor turning control mode can be performed, when at least one of the second control unit and the second motor malfunctions in the state where the first control unit and the second control unit perform the two-motor turning control mode, the clutch is disconnected and rotation angles of the first motor and the second motor are controlled by the first control unit and the second control unit depending on a rotation angle of the input shaft in the two-motor turning control mode, the clutch is connected and a torque of the first motor is controlled by the first control unit depending on the torque detected by the torque detection unit in the one-motor assist control mode, and the clutch is disconnected and the rotation angle of the second motor is controlled by the second control unit depending on the rotation angle of the input shaft in the one-motor turning control mode. a steering input mechanism (St IN) in which an input shaft is rotated by a steering operation by a driver; a turning output mechanism (St OUT) configured to turn a wheel by a rotation of an output shaft; a clutch configured to couple the input shaft and the output shaft such that the input shaft and the output shaft are couplable and decouplable; a first motor capable of providing driving force to the turning output mechanism (St OUT); a second motor capable of providing driving force to the turning output mechanism (St OUT); a first control unit configured to control driving of the first motor; a second control unit configured to control driving of the second motor; and a torque detection unit configured to detect a torque of the output shaft, wherein at least the first motor and the torque detection unit are configured as an integrated composite component, the second control unit is configured to perform a one-motor turning control mode when at least one of the first control unit, the first motor, and the torque detection unit malfunctions, in a state where the first control unit and the second control unit perform a two-motor turning control mode, the first control unit is configured to perform a one-motor assist control mode even in a state the one-motor turning control mode can be performed, when at least one of the second control unit and the second motor malfunctions in the state where the first control unit and the second control unit perform the two-motor turning control mode, the clutch is disconnected and rotation angles of the first motor and the second motor are controlled by the first control unit and the second control unit depending on a rotation angle of the input shaft in the two-motor turning control mode, the clutch is connected and a torque of the first motor is controlled by the first control unit depending on the torque detected by the torque detection unit in the one-motor assist control mode, and the clutch is disconnected and the rotation angle of the second motor is controlled by the second control unit depending on the rotation angle of the input shaft in the one-motor turning control mode.