A rapid method for determination of arsenic( As)，lead( Pb)，cadmium( Cd)，chromium( Cr) and mercury(Hg) was developed in the water-soluble fertilizer containing alginic acid by energy dispersive X-ray fluorescence spectrometry(EDXRF).With weighing，adding acid and vortex mixing，the sample was added into the sample cup and scanned by EDXRF directly，the qualitative analysis was carried out by characteristic energy spectrum peak of the elements and the quantitative analysis was performed by standard addition method.The results showed that the method had good selectivity and there was no interference on the energy spectra of the five heavy metals from the matrix elements of the water-soluble fertilizer containing alginic acid；the standard addition method could effectively overcome the matrix effect of the water-soluble fertilizer containing alginic acid and with the method the five metals could be quantified accurately；the linearity of the method was also accepted with R2 > 0.9950；the limits of detection were 0.21 ～ 6.70 mg/kg and the limits of quantitation were 0.70 ～ 22.40 mg/kg；the recoveries were 96.83% ～ 110.63%.The intra-day relative standard deviations were 0.58% ～ 6.36%，and the intra-day relative standard deviations were 0.64% ～ 6.61%.The method is simple，rapid，accuracy and reliability，it can meet the needs of rapid quality monitoring of As，Pb，Cd，Cr and Hg elements in the water-soluble fertilizer containing alginic acid.This study provided a good example for promoting the application of EDXRF technology in the agricultural field.