A method is disclosed to detect the voltage of a limit switch in an optical disc drive. The method includes following steps: loading an optical disc when the voltage of the limit switch is at a high level, completing the disc loading process when the voltage is changed to a low level, sampling the voltage of the limit switch predetermined times when the voltage is changed to the high level again, detecting the sampling voltages, completing the disc ejecting process when the sampling voltages are all at the high level, and determining a voltage bouncing to maintain the disc loaded status to avoid disc ejection misjudgment of the optical disc drive when the sampling voltages are not all at the high level.