A piezoelectric-driving optical lens module is disclosed, including a lens body a piezoelectric actuator for providing a driving force, and a position sensor for detecting position variations. The lens body includes at least a hollow base body, a lens barrel exhibiting axial freedom of movement positioned inside the hollow base body, and a lens set disposed inside the lens barrel. The lens barrel is driven by a piezoelectric actuator to move the lens set along the optical axis to achieve the optical functions of zooming and focusing. The position sensor is configured to detect the axial position of the lens barrel with respect to the hollow base body, thereby providing a simple structure to improve on the drawbacks of prior techniques.