Abstract: In order to study the codensification and co-combustion characteristics of blends of cotton stalk char and bio-tar,with pressure,temperature and bio-tar content as experimental factors,and the orthogonal test method is carried out to research on the influence of codensification conditions on compressive strength,drop strength,relaxed density and water absorption,and in this study the combustion characteristics of cotton stalk char and bio-tar mixed samples is analyzed by a thermogravimetric analyzer. The test results show that the optimal codensification process parameters as follows,pressure 8 k N,temperature 20 ℃,and bio-tar content 6%.The combustion characteristic index（28.86-24.21）×10^-8K^-3·min^-2 of the mixed samples of cotton stalk char and bio-tar decreases with the increase of bio-tar content（0-6%）,It shows that adding appropriate of bio-tar to the cotton stalk char can obtain good codensification and combustion performance.