Abstract: The experiment was studied on the effects of different combination of Potassium Fertilizer in Arid Land Broomcorn millet （Panicum miliaceum L.） of Ningxia southern region, the results indicate that , Potassium Fertilizer affects yield of Broomcorn millet significantly, the consumption per hectare from 0 kg to 30kg ,90kg, 120kg, 150 kg, the yield has great changes, the maximum is 4744.65kg/hm2, the minimum is 3581.85 kg/hm2,fertilizer combination of K2O 60kg/hm2,N 139.2kg/hm2,P2O5 129kg/hm2 has the best effect on yield, increased the yield by 8.9%-24.5% compared with other treatments.