In this paper，the new farmland soil fertility index after the wild grassland reclamation was studied using the method of the analytic hierarchy process(AHP)and weight comparison method，the weight of new farmland soil fertility index was distributed and evaluated，soil fertility index in this area，and the maximum limit factors of new farmland soil fertility was presented in Weibei Plateau.The results showed that: The soil fertility weight index of new farmland were that pH was 0.22，conductivity was 0.03，SOM was 0.22，TN was 0.22，AP was 0.15，AK was 0.10，texture was 0.06 in Chengcheng county,Weibei PlateauThe soil fertility comprehensive index of new farmland was in the distribution of the scores between 38 and 66 in Chengcheng county，and the average value was 54.The comprehensive scores of the soil fertility of 90% the area were between 45 and 65，and the half area of the new farmland soil fertility index was 50 to 60.The areas in the highest score and the lowest score were accounted for 5% and 3%，respectively.The main factors that caused the low soil fertility index were the low contents of AP，SOM，AK，TN，the influence was AP>SOM>AK>TN.Combining the method of AHP and weight comparison method was a good application in the soil fertility comprehensive evaluation.