It is a vitally important task to achieve control of the weight and center of gravity of lightship during building a new ship. If the lightship weight is slightly out of control, the deadweight inadequacy and a deviation from the initial design target will be caused. The basic performance and function of a ship at sea are also resulted. Furthermore, if the lightship weight is incompletely under control, it will bring about an unsafe vessel, ship-delivery difficulty and a severe loss for shipbuilder. Docking arrangement is optimized to allocate by using the state-of-the-art finite element method to analyze the lightweight distribution as the load and the ship girder as a beam; in addition, the dock is recognized as a spring-liked elastic foundation subjected to compression only. It is verified by comparison between measurement of the lightship weight by means of the weight control system on land and the traditional inclining experiment. Based on the results, it can be shown that the whole system is reliable, available and efficient. The load cell is utilized as a component of the weight control system to measure the compressive force (i.e., ship weight) at a specified dock. The main function of the system is to determine the lightweight and its C.G. on-land construction instead of the time-consuming and labor-wasting traditional way. The presented methodology will be beneficial for weight control of a new-ship building in the future.