This paper introduces a data processing system for the three-dimensional information of double parallel-joint coordinate measuring machine (PD-CMM).The intelligent sensor units, which consisted of angle sensors, temperature sensors, microcontroller, are set in each joint and arm. The data are mainly the grating's output signal of each joint and the temperature change of each arm. The system samples and processes the data, then communicates with the host computer through USB interface. The simulation and experiments show that the data processing system works well.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.