In order to provide a basis for rational application of synergistic compound fertilizer, the effects of nitrogen reduction application of synergistic compound fertilizer on wheat and maize yield and nutrient efficiency were explored through a field experiment of different synergistic compound fertilizers and nitrogen reduction application in Guoyang county, Anhui Province from 2017 to 2020. There were nine treatments in the experiment: No fertilizer (CK), conventional compound fertilizer (CF), humic acid compound fertilizer (HF), amino acid compound fertilizer (AF), alginate compound fertilizer (SF), conventional compound fertilizer 20% N reduction (CR), humic acid compound fertilizer 20% N reduction (HR), amino acid compound fertilizer 20% N reduction (AR) and alginate compound fertilizer 20% N reduction (SR).The results showed that the order of average yield of wheat and maize without N reduction was AF > SF > HF> CF, SF > HF > AF > CF, respectively. The average yield of wheat and maize treated with N reduction was AR > SR > HR > CR and HR > SR > AR > CR, respectively. The order of annual average yield was SF >