The invention discloses a preparation method of a soluble inorganic phosphorus and arsenic adsorption membrane. According to the preparation method of the adsorption membrane, cerium oxide nanoparticles are dispersed in an acrylamide solution, and acrylamide polymerization reaction is carried out to fix the nanoparticles uniformly in polyacrylamide gel. The preparation steps include: dispersing cerium oxide nanoparticles into the acrylamide solution, adding ammonium persulfate and tetramethylethylenediamine, mixing the substances evenly, then injecting the mixture into a two-glass plate gap clamping a U-shaped sheet, conducting horizontal placement at room temperature for 30min, then opening the glass plates and taking out a gel membrane, soaking the gel membrane in deionized water for 24hto remove unreacted reagent, cutting the gel membrane to a circle with a diameter of 2.5cm to make the adsorption membrane. The preparation method of the adsorption membrane provided by the inventionhas the characteristics of simple operation and good repeatability. The adsorption membrane has large adsorption capacity and good selectivity on soluble inorganic phosphorus and arsenic, can be preserved for a long time in a solution, and has broad application prospect in the fields of analytical chemistry and environmental analysis.