Based on a 16-year located experiment, this paper studied the yield-increasing effect, yield-stabilizing feature and contribution rate of fertilizers to maize yield under different fertilization and precipitation conditions. The results showed that fertilization and precipitation had obvious influences on crop output. In normal precipitation years the yields were the highest and the yield-increasing effect of chemical fertilizers was the best. In the higher precipitation years the yield was the highest under NPK treatment and was lower under non-nitrogen treatments, but P and K could increase the stress resistance of maize. The contribution rate of chemical fertilizers to maize yield was N＞P＞K and maize yield under K treatment was lower than CK treatment in normal or higher precipitation years. It suggests that K was not a limiting factor for crop yield and K could increase maize yield when applied with N. Proper nutrients and water supply would improve the contribution rate of fertilizers to maize yield and promote the interaction between fertilizers on yield-increasing effect.