Electric power steering device and corresponding steering system

The invention discloses an electric power steering device and a corresponding steering system. The electric power steering device comprises a power motor of which the output shaft is in transmission connection with a steering shaft, and a controller which is electrically connected with the power motor so as to control the output of the power motor according to a received control signal. Preferably, the electric power steering device is used for a commercial vehicle. The steering system comprises a steering wheel, the steering shaft, and the electric power steering device, wherein one end of the steering shaft is connected to the steering wheel so as to rotate synchronously with the steering wheel, while the other end of the steering shaft is connected to wheels by virtue of universal joints. As a result, the motor is used for providing power to the steering shaft of the steering shaft, and therefore, the problem of heavy steering in the operation process of a driver is avoided, and the problems of increased motor power loss, increased oil consumption and the like also are avoided.