Objective To improve the precision and accuracy of atomicfluorescence spectrometry for the determination of total seleniumcontent. Methods This article analyzes the factors affecting thedetermination of total selenium in geochemical samples by hydridegeneration atomic fluorescence spectrometry, and explores threeinfluencing factors: sample digestion, instrument cleanliness, andcoexisting ion interference. Optimized the sample digestion process,summarized the issues that should be noted in the instrument during thesample determination process, as well as the common methods foridentifying and eliminating coexisting ion interference. Results Thefeasibility of the method has been verified through 13 national firstlevel standard reference materials, the detection limit of the method is ${0.006}\mathrm{{mg}}/\mathrm{{kg}}$ ,which is lower than the detection limit of DZ/T 0279.14-2016 (0.01mg/kg). The relative standard deviation of the test standard substancewere ${1.9}\%\sim {7.9}\%$ , and $\left|{\Delta\mathrm{{lg}}C}\right|$ were all less than 0.1 . The precisionand accuracy meet the requirements of DZ/T0011-2015 Geochemical CensusSpecification (1:50000). Conclusion Effectively solved the problem ofunstable quality in the determination of total selenium by atomicfluorescence spectroscopy, and improved precision and accuracy.