The invention discloses a middle axle reverse braking signal transmission device with an electric bicycle operating state determination function. The device is characterized in that dual-magnetic rings are installed on a driver plate and a middle axle gear wheel that are used as reverse braking deflection components and two phase induction hall units for sensing the dual-magnetic rings respectively are also arranged; and thus a controller can determine whether an operating state of a motor is a moving forward state, a free state or a reverse braking state by obtaining phase difference signals outputted by the two phase induction hall units and then sends out a proper instruction to the motor based on the determination, thereby meeting a speed reducing or stopping requirement in a non-reverse-braking state. Therefore, a runaway speed phenomenon of an electric bicycle can be prevented. Besides, an elastic reset element is also arranged between the driver plate and the middle axle gear wheel and a pedal force in a reverse braking state can be changed by adjusting an elastic force, so that the proper braking feedback force can be provided for the foot and thus a zero-force pedaling phenomenon or a non-in-place pedaling phenomenon can be avoided; and thus the comfortable level of product use can be improved; and a certain buffer function can be realized, so that the motor can be protected and the service life can be prolonged.