Disclosed herein is a signal processing apparatus for a wheel speed sensor, which monitors a current input to a wheel speed sensor so as to prevent the current from being excessively supplied to the wheel speed sensor. That is, the present disclosure relates to the signal processing apparatus for a wheel speed sensor, which monitors the current input to the wheel speed sensor in a duplex manner. The signal processing apparatus for a wheel speed sensor include a sensor input terminal unit to which a sensing signal of a wheel speed sensor is input, and a normality determination block determining whether or not the sensing signal is normal.