This paper studies the effect of nitrogen and phosphorus fertilizer on yield and forage quality of sequential cropping silage maize. The result of field experiment shows that fertilizing nitrogenous fertilizer at the jointing stage can significantly improve the yield and forage quality of silage maize, but it is not very effective to apply phosphorous fertilizer for higher yield. The yield of silage maize is the highest which is 54 972 kg·hm~(-2) by applying nitrogenous fertilizer 90 kg·hm~(-2) at the jointing stage. And applying more nitrogenous fertilizer only can improve the forage quality. Applying nitrogenous fertilizer at the male tetrad stage can significantly improve the forage quality of sequential cropping silage maize.