Bamboo charcoals (BC) are prepared at different pyrolysis temperature (350, 450, 500, 600 and 700 °C) with 2 h residence time and at 15 °C/min heating rates. The biochar yields, thermal stability, molecular groups, surface topography, and pore structure were characterized to explore the effect of pyrolysis temperatures on the characteristics of BCs. The results show that the biochar yield has decreased while the thermal stability of BC has increased with the increasing pyrolysis temperature. With the increase of temperature, C-C and C-H bond of aromatic compounds are enhanced to form stable components. The highest specific surface area and pore volume is obtained in the BC prepared at 500 °C with the value of 40.754 m2/g and 0.04738 cm3/g. The optimum temperature for achieving sufficient structure and good properties in fiber is 500 °C. And then, PET/BC fibers are prepared via melt-blend spinning. The mechanical capacity, thermal behavior, moisture absorption and far infrared emission properties of PET/BC fibers with different BC content have been investigated. It is found that the fiber has most desired comprehensive property with the BC content was 2%. At this composition, the tensile strength of the PET is 3.01 cN/dtex, the moisture absorption increases by 50%. The far-infrared imaging of the fabric shows highly temperatures raise of 44.8 °C within 30 s.