Abstract: A method for detecting an obliquity of an optical disc drive is disclosed. The method includes the following steps: setting up and storing a function between the obliquity and a central error signal bias by performing a current level calibration upon a plurality of obliquities of the optical disc drive predetermined to be tested to obtain corresponding central error signal biases; performing the current level calibration upon an objective lens of the optical disc drive; obtaining a calibrated central error signal bias; and acquiring the obliquity of the optical disc drive by interpolating or extrapolating the calibrated central error signal bias according to the stored function between the obliquity and the central error signal bias.