Real-time, online, accurate, and rapid detection of eutrophic element nitrogen in water was achieved using aerosol assisted laser-induced breakdown spectroscopy (LIBS) in this work. In response to the limitation that the liquid lifting capacity of traditional concentric atomizer is affected by liquid physical characteristics, a micro-volume syringe pump is used in this work to achieve the same liquid lifting volume of samples with different salinity. As a result, the average relative standard deviation(D_RSAV) of the absolute intensity of N I peak at 746.831 nm is reduced from 19.51% to 6.78%, the limit of detection (LoD) is improved from 5.45 mg/L to 1.57 mg/L, and the linear correction coefficient R², average relative error (E_R), and root mean square error of cross validation (E_RMSCV) are improved from 0.2830, 45.80%, and 23.96 mg/L to 0.9043, 10.33%, and 4.28 mg/L, respectively. The results of this work indicate that the liquid aerosol assisted LIBS with the assistance of a micro injection pump for sample injection can be applied for accurate and sensitive detection of nitrogen in water.