Using the amount of water，nitrogen (N) and potassium (K2O) as the experimental factors，the three-factor five-level two-purpose rotation combination was designed by field experiments to study the effects of different irrigation and fertilization on potato yield and water utilization efficiency under the condition of drip irrigation and fertilization.The results showed that:(1)Both irrigation and nitrogen application had significant effects on potato yield and water use efficiency，and the main effect of nitrogen application was greater than that of irrigation，while the main effect of potassium application was not significant；(2)The results of single factor effect analysis showed that the yield and water use efficiency of potato increased first and then decreased with the increase of irrigation and nitrogen application；(3)The interaction between water and nitrogen had a significant impact on potato yield and water utilization efficiency.Reasonable water-nitrogen combination could promote potato yield formation and efficient utilization of water fertilizer resources，high irrigation combined with higher nitrogen application led to the highest yield，medium or high irrigation combined with higher nitrogen application led to the highest water utilization efficiency.Under the experimental conditions，the optimal water and fertilizer schemes for the target yield of potato between 48000 and 60000 kg·hm-2 were managed by irrigation of 1569.0～1671.0 m3·hm-2，nitrogen application of 288.0～327.0 kg·hm-2 and potassium application of 163.5～196.5 kg·hm-2.Under the water and fertilizer management，the water use efficiency of potato could reach 178.88～179.03 kg·hm-2·mm-1.