We develop the kinematic model of portable coordinate measuring arm (PCMA) based on the research on its mechanical characteristics and working principle, and present a comprehensive thermally-induced error correction model for PCMA. Based on the model and nominal data provided by a highly accurate coordinate measuring machine, the technique for thermally-induced error compensation of PCMA is presented along with measuring a standard artifact at the corresponding temperature field. Experimental results demonstrate that the deviation of PCMA at different temperatures is controlled in the range of ±10 μm using this technique to calibrate the PCMA.