A dynamic real-time horizontal datum measuring system was designed and the feasibility of the measurement system used to measure the twist angles of Yuan Wang tracking ship was discussed. Then the measuring principle and the measuring errors of the system when it measured transverse and vertical twist angles were analyzed. According to the measuring demands, the key technical specifications were determined and the measurement accuracies on transverse and vertical twist angles were analyzed. The analyzed results show that the measurement errors for transverse and vertical twist angles of the measurement ship are not more than 3″, and the measuring distance is without any restrictions in theory, much longer than 200 m(the length of Yuan Wang surveying vessel). A measuring experiment was performed on the transverse and vertical twist angles of the Yuan Wang tracking ship when it is a docking state, results show that the proposed method is feasible, and it can not only increase the measurement accuracy, but also overcomes the drawbacks from the traditional large steel pipe based the method. It is characterized by compact dimensions, lower weights and wider application fields.