A modular laser 3-dimensional scanning system based on the rotary-laser theodolite positioning network is designed. As a positioning measurement system combining the measuring principle of frontage intersection of theodolite and the concept of GPS, the Rotary-laser Theodolite Positioning System (RLTPS) can realize the parallel measurement of spatial coordinate of multiple Photodiode Detector (PD). The spatial position of the laser probe is determined by the coordinates of the three PD, therefore, the portable laser 3-dimensional scanning system is realized, which can be used to the measurement in the industrial fields. The feature point cloud data of objects surface are measured by the designed Modular Laser 3-dimensional Scanning System and the experimental results show that the measurement system can satisfy the application requirements.