Abstract: PURPOSE To investigate the thermal expansion coefficient of different processing parameters upon the Co-Cr alloy prepared by selective laser melting (SLM) technique, in order to provide technical support for clinical application of SLM technology. METHODS The heating curve of self-made Co-Cr alloy was protracted from room temperature to 980℃ with DIL402PC thermal analysis instrument, keeping temperature rise rate and cooling rate at 5 K/min, and then the thermal expansion coefficient of 9 groups of Co-Cr alloy was measured from 20℃ to 500℃ and 600℃. RESULTS The 9 groups thermal expansion coefficient values of Co-Cr alloy heated from 20℃ to 500℃ were 13.9×10-6/K,13.6×10-6/K,13.9×10-6/K,13.7×10-6/K,13.5×10-6/K,13.8×10-6/K,13.7×10-6/K,13.7×10-6/K,and 13.9×10-6/K, respectively; when heated from 20℃ to 600℃, they were 14.2×10-6/K,13.9×10-6/K,13.8×10-6/K,14.0×10-6/K,14.1×10-6/K,14.1×10-6/K,13.9×10-6/K,14.2×10-6/K, and 13.7×10-6/K, respectively.CONCLUSIONS The results showed that the Co-Cr alloy has good matching with the VITA VMK 95 porcelain powder and can meet the requirement of clinic use.