Embodiments of the present invention relate to the technical field of fingerprint sensor detection, and in particular, relate to a method and system for detecting a thickness of a protection layer of a fingerprint sensor. The method includes the following steps: step a: collecting fingerprint data via a fingerprint sensor, the fingerprint sensor comprising a plurality of chip sensing units, arranged in an array； step b: calculating a derivative of the fingerprint data, normalizing the derivative of the fingerprint data, and calculating an integration according to the normalized derivative of the fingerprint data； and step c: acquiring a thickness of a protection layer of the fingerprint sensor according to the integration result.
