Abstract: 2F-6-BP1 variable rate assorted fertilizer applicator was designed to solve the problem of lacking suitable variable rate fertilizer application with big power tractor in China. By accessing the speed of the tractor via a speed indicator, and ascertaining the location of the applicator in the field via GPS system, the expert system of the applicator could determine the dispensing rate of the fertilizers based on the preloaded fertilizer maps storing the desired fertilizer level. The expert system of the applicator adjusted fertilizing to attain precision fertilization according to the feedback fertilizer flow. The system design,working process and experiments of the applicator were also explained in the paper. The experiment results indicate that the maximal weighing error of the variable rate fertilizer applicator is 0.65% and the fertilization precision can reach above 95%. Therefore, the variable rate fertilizer is good economic and practical in the precision agriculture.