ing at the low precision problem of the three-dimensional shape robot measurement system composed of industrial robots and topographic sensors, a three-dimensional shape complex curved surface measurement system based on iGPS (indoor global positioning system) is proposed. The overall design scheme of the proposed measurement system is introduced and a mathematical model is established for it. Experiments on length measurement accuracy and repeated measurement accuracy are carried out. The experimental results verify the accuracy and reliability of this measurement system for large-scale complex curved surface topography measurement. The shape measurement of large-sized workpiece with double arched surface is carried out. The measurement results verify the feasibility of this measurement system.