Ge20Sb15Se65 chalcogenide glasses with low impurity absorption are prepared and fibers with different diameters are drawn. The power delivery characteristics of CO2 laser (10.6 μm) through these fibers are experimentally investigated. The experiment results show that the glass prepared has good anti-crystallization property, and the infrared transmission in the 5-11 μm band is about 64%. Under high power CO2, heat accumulation caused by the light absorption makes the temperature on the fiber end surface rise rapidly, and the melting damage is observed on the end surface of the Ge20Sb15Se65 glass fiber. The maximum output power of 809 mW with the input power of 5267 mW is obtained by using the fiber with a diameter of 800 μm. The output power density is 161 W/cm2 and the delivery efficiency is 16%. The experimental results are basically consistent with the theoretical calculation results.