A bicycle transmission hub includes: a hub shaft to input a rotation force is input, the hub shaft having first pawls arranged on the outer peripheral surface thereof; a transmission controller for controlling the first pawls to appear and disappear; driving gears, each having a ratchet formed on the inner peripheral surface thereof to receive a rotation force by the first pawls, the driving gears having a different number of teeth, the hub shaft extending through the center of each driving gear; driven gears engaged with the driving gears, respectively, having a different number of teeth, and rotating; an output wheel rotating while being coupled to a driving gear adjacent thereto among the driving gears and having a second pawl disposed on the outer peripheral surface thereof; and a hub shell having a ratchet formed on the inner peripheral surface thereof to receive a rotation force by the second pawl.