The active carbon was modified by Ni(NO3)2 for adsorption methane which from the low concentration coal-bed gas. In order to optimization the conditions of nickel modified active carbon the Box-Behnken central composite design experiments which based on the univariate tests and response surface method were used. The result showed that the optimized conditions of nickel modified active carbon were Ni(NO3)2 concentration 0.21 mol/L, temperature 730℃, and time 67 min. Under the conditions, the breakthrough time was 550 s, adsorption capacity was 58.07 mL/g, the modified active carbon has superior adsorption performance.