The invention relates to a preparation method of soil heavy metal adsorption fiber. The preparation method comprises the following steps that polyvinylpyrrolidone and attapulgite powder are added into an ethanol solvent for ultrasonic blending to form a polymer solution; the prepared polymer solution is put in an injector; a positive electrode of a high-voltage electrostatic generator is connected with a syringe needle; a negative electrode of the high-voltage electrostatic generator is connected onto a clean bare electrode; a nanometer heavy metal fiber adsorption material is prepared; a NaOH solution is added into the nanometer heavy metal fiber adsorption material; the mixture is stirred for dissolution; carbon disulfide is added drop by drop; after the dripping completion, the temperature is gradually raised; then, distilled water is used for repeatedly washing the fiber material; the soil heavy metal adsorption fiber can be obtained. The preparation method has the advantages that the mixed solution of the polyvinylpyrrolidone and the attapulgite powder is prepared into the nanometer heavy metal fiber adsorption material by the high-voltage electrostatic generator; then, the nanometer heavy metal fiber adsorption material is modified; the obtained soil heavy metal adsorption fiber has a good adsorption effect on heavy metal ions.