Laser tracker system (LTS) is an advanced 3D coordinates measuring system for large size. It can measure large 3D coordinates with advantages of broad range, high speed and high accuracy. However, when the size of having been measured large-scale part (such as airplane and shipbuilding) is larger than the LTS measuring range, it can not measure all of the required features of components in one location, which profoundly affect the LTS measuring scope and accuracy. In order to solve measuring problem for large-scale parts, a new method of frog-jumping is proposed based on the principle of using LTS to measure more than three frog-jumping spheres under the new and old coordinate system. The corresponding mathematical model of frog-jumping is established. Intensive experimental studies have been made to check validity of proposed method; the results show that using this technology the measurement of large-scale parts all features is realized effectively under the required accuracy constraints.