A set of experiments were designed to research on the mechanical characteristics of laser driving lightcraft,and the minimum laser power density needed to drive the lightcraft (weight 1.010 kg) is measured to be 71.986 ×109 W. cm-2 during the confined laser ablation of targets in vacuum. A set of parameters are discovered important to improve the propulsion efficiency, such as the restraint layers on the targets (the K9 glass is the optimal), and larger laser power density. In view of the impracticality of the confined ablation, we propose the applications of those target materials that cannot only produce powerful plasma propulsion but also can be used in repetitively pulsed laser.