Abstract: In order to improve the efficiency of oil shale pyrolysis and the utilization value of semi-coke, this paper co-pyrolyzed Huadian oil shale and waste tire.The weight loss behavior, product yield and composition properties of co-pyrolysis were investigated by thermogravimetric analyzer and aluminum retort reactor.The synergistic effect was analyzed based on the difference between experimental and calculated values.The results show that co-pyrolysis can promote the release of volatile matter, the actual weight loss is higher than the calculated value at 500 ℃, and reaches the maximum value of 2.86 % when the proportion of waste tire is 80 %.The mixed pyrolysis of oil shale and waste tire has the effect of "increasing oil and reducing water".When the waste tire accounts for 50 %, the actual oil yield is 32.91 %, which is 1.5 % higher than the calculated value, and the actual water yield is 1.20 % to 1.77 % lower than the calculated value.Meanwhile, the content of heavy components with boiling point higher than 350 ℃ in the pyrolysis oil increases.There is higher yield of C₁~C₄ hydrocarbons from waste tire pyrolysis, and the calorific value of semi-coke is up to 30.43 MJ/kg.Co-pyrolysis can also improve the calorific value of pyrolysis gas and semi-coke.