A lens actuating device is applicable in a lens module. The lens module has at least a housing and a lens support in the space formed by the housing. The lens actuating device has at least a base disposed in the housing, a piezoelectric element disposed on the base for generating kinetic energy, a clamping component disposed on the piezoelectric element and a linkage element coupled to the lens support and clamped in the clamping component. The clamping component makes a corresponding motion upon receiving a kinetic energy created by the piezoelectric element, which allows a stick-slip friction to be generated in the clamping component to actuate the lens, thereby achieving optical zooming or focusing and avoiding the shortcomings of the prior art using for example a voice coil motor or a stepping motor.