Gyroscope is well known as a sensor but also used as an actuator. In the beginning of 20th century, research that related with gyro-monorail by using a gyro-actuator was conducted. Later, the research on a gyro-bike system was reported in 1970's. Then, the self-sustaining body bike has been reported up until now. In this paper, we propose an unmanned self-sustaining driving control bike in a straight motion using gyro-actuator which is controlled by a computer. First, we use the link model to construct the linear equation of motion. Next, we develop the modeling of a gyro bike system by using the link model theory. Then, we conduct the experiments to confirm the result of the theory.