An optical measuring device (20) for measuring a micro displacement or a micro vibration of an object (28) includes a laser emitter (21), an amplifying lens module (23), and a photoelectric sensor (25). The laser emitter is configured for emitting a laser beam at the object so that the object reflects the laser beam and forms a beam reflection. The amplifying lens module is disposed between the photoelectric sensor and the object for the beam reflection passing there through. The amplifying lens module has an optical axis parallel to the beam reflection. The photoelectric sensor includes a receiving plane (251) for perpendicularly receiving the beam reflection reflected by the object.