Abstract: In order to optimize preparation parameters of coal based activated carbon using Yulin coal as the raw material,the carbonization and activation test equipment for preparation of activated carbon was designed and built. The experiment factors influencing the activated carbon performance were carried out.The orthogonal test method was used to test the carbonization process and activation process.The COD removal capacity of chemical wastewater was used as the main evaluation method to determine the optimal process parameters. The structure characteristic of the activated carbon obtained under the optimal process parameters were analyzed by BET and SEM test to find out the main factors affecting the COD removal ability. The results show that activated carbon is prepared by using Hongliulin coal as raw material by the pyrolysis activation method.The influence degree of raw coal pyrolysis process factors are pyrolysis temperature,heating rate,and pyrolysis residence time,successively.The semi-coke iodine adsorption value is 135.66 mg/g in the best pyrolysis process parameters with 600 ℃,2 ℃/min,and 30 min.It shows that the semi-coke formed by the coal pyrolysis process has owing preliminary adsorption capacity and pore structure,which is conducive to further activation to turn into the activated carbon. The influence degree of the semi-coke activation process factors in order are activation temperature,activation time,and steam penetration rate. The best activation process parameters are activation temperature of 850 ℃,activation time of 3 h,and steam introduction rate of 15 L/min.The highest chemical wastewater COD removal rate of the activated carbon obtained in the best activation condition is 70.97%,which can be treat effectively.The specific surface area of the activated carbon is 671.50 m2/g,and there are both micropores and mesopores in different quantity. The distribution of micropores is mainly 0.7 nm,and the distribution of mesopores is 5-20 nm.The research indicates that the Yulin coal can be processed to produce activated carbon with rich mesopores under optimizing process parameters,which can effectively remove chemical wastewater COD.