Field experiments were conducted to study the effects of synergetic addition in the fertilizers such as polyaspartic acid, humic acid, and nitrification inhibitor DMPP (3,4-dimethyl pyrazophosphate) on the nitrogen transformation of rice surface water and rice yield by planting single cropping rice "shaojing 18" in paddy field. The results showed that the total soluble nitrogen, ammonium nitrogen and nitrate nitrogen concentrations in the rice surface water were significantly increased by fertilization. With the application of synergists such as polyaspartic acid, DMPP, humic acid and so on, the average soluble total nitrogen concentration in the rice surface water decreased by 14.1%, 15.8%, and 7.3%, ammonium nitrogen increased by 10.6%, 27.5%, and 8.6%, and nitrate nitrogen declined by 31.8%, 46.7%, and 26.9%, respectively, which helped to reduce the risk of non-point source pollution caused by the nitrogen runoff loss to water environment. Polyaspartic acid, DMPP, and humic acid application increased rice grain yield by 6.2%, 7.8%, and 2.4%, and increased straw yield by 10.8%, 6.1%, and 4.0% respectively. Compared with common fertilizers, synergist addition in the fertilizers can reduce the total nitrogen content in the rice surface water, and better promote the growth of rice and increase the yield.