In order to coordinate the supply and distribution of green manure nutrients，the pattern of multiple cropping of green manure after wheat was optimized. A field experiment was carried out in Qinghai province to study the effects of chemical fertilizer addition(F0:no fertilizer；F1:fertilizer)and planting methods(MC:mono-cropping of common vetch，MR:mono-cropping of rape，MCR:mixed cropping of common vetch and rape)on green manure biomass，water use efficiency，nutrient absorption，soil nitrate nitrogen residue and system apparent nitrogen balance. The results showed that the total biomass，N，P，K uptake and water use efficiency of green manure were MC>MCR>MR，no matter whether fertilizer was applied or not. Fertilization significantly increased the biomass and water use efficiency of MCR by 65.01% and 83%，respectively；The potassium absorption of MC and nitrogen，phosphorus and potassium absorption of MCR were significantly increased by 25.97%，79.73%，74.52% and 70.96%，respectively. The residual amount of soil nitrate nitrogen in the 0～60 cm layer of each treatment increased gradually with the depth of the soil layer. Under fertilization，the soil nitrate nitrogen in the 0～20 cm layer of MC，MR and MCR treatments was mainly used，and fertilization would lead to nitrate nitrogen leaching to the lower soil for MC and MR. Under different planting patterns，the apparent mineralized nitrogen showed as MCR>MC>MR. Fertilization significantly improved the biological nitrogen fixation of MCR and the nitrogen absorption of crops by 124.6% and 79.7%，respectively. This study can provide scientific basis and theoretical reference for green manure planting technology in Qinghai province.