A deflection device of steerable endoscope includes a first base, a second base, elastic reposition members and tendon wires. The second base is located above the first base along the endoscope center axis. The elastic reposition members are inlaid between the first and the second bases. Each elastic reposition member includes a first plate connecting to the first base, a second plate connecting to the second base, and a waveform bar connecting the first and the second plates. The amplitude of the waveform bar is not parallel to the endoscope center axis. The tendon wires are located on the two opposite sides of each elastic reposition member. The tendon wires are parallel to and distant from the endoscope center axis. Bending of the steerable endoscope is precisely controlled, and structure of the deflection device is simplified in the invention.
