A motor position signal processing apparatus electrically connected to a signal processor and an optical encoder of a motor control system includes a first switch, a second switch, a first signal integration amplifier, a first separator, a second signal integration amplifier, a second separator, a third signal integration amplifier, a third separator, a fourth separator and an inverter. An enable signal outputted by the signal processor is processed by the inverter to switch the operation to the first switch or the second switch. An incremental signal outputted by the optical encoder, a motor mechanical position and a reset correction signal are processed by the first, second and third signal integration amplifiers and transmitted to the signal processor for controlling the operation of a motor.