The invention provides a preparation method of an ABS (acrylonitrile butadiene styrene) standard sample for X-ray fluorescence spectrometry. The method comprises steps as follows: S1, a powdery raw material containing target metal elements is prepared and screened with a 400-mesh screen; S2, ABS resin with the content of target metal elements lowering than a detection limit of an instrument is selected, and no antioxidant and no plasticizer are contained in the ABS resin as is determined; S3, a lubricant with the mass accounting for 2 per mill-3 per mill of that of the ABS resin is added, and the ABS resin and the lubricant are mixed uniformly; S4, the additive amount of metal is determined in the rules shown in the specification according to the requirements for the content of metal in a standard sample; S5, the powdery raw material and the ABS resin mixed in S3 are put into a high-speed mixer and mixed at a lower speed for the first time; a few quantity of lubricants are added and mixed at a higher speed for the second time; S6, the mixed materials are heated, melted and subjected to extrusion molding and granulation in an extruder; the granular material is made into standard samples. According to the method, the standard samples with the metal content approaching to target content can be obtained and are very uniform and good in repeatability.