A steering wheel apparatus for adjusting stiffness and receiving a pressure is provided. The apparatus includes a rim having a ring-shaped frame structure and an air container disposed around an outer surface of the rim. An outer sheath covers an outer surface of the air container and an air nozzle is connected to an inside of the air container. A pressure sensor is mounted to the rim to detect a pressure by which the steering wheel apparatus is gripped and an air compressor and a vacuum pump are connected to the air nozzle. A steering controller analyzes signals input from sensors to maintain an air pressure of the air container and operate the air compressor or the vacuum pump when present condition information is satisfied. An engine controller analyzes a signal input from the pressure sensor and when the signal corresponds to a predetermined pressure or greater decelerate the vehicle.
