The present invention relates to electric bicycle speed control device and method. According to the present invention, a torque of a motor for driving a wheel is controlled so that a speed of a pedal driven by a user follows a speed of the wheel, and a torque of the pedal is also controlled by applying an assist level according to the torque of the motor. Therefore, even in an electric bicycle with a chain, it is possible to feel a feeling of the pedal like a bicycle with a chain, and it is possible to adjust the force applied to the pedal according to the assist level.