Abstract: To improve the efficiency of mineral exploration and shorten the anomaly verification period, it is of practical significance to determine geological samples quickly in field. The energy dispersive X-ray fluorescence spectroscopy (EDXRF) is used to study the on-site determination of 20 elements such as Cu, Pb and Zn in geological samples. The uncertainty of the method is evaluated. Through performance verification of the method, the quality control indexes of all elements in the geological samples conform with the requirements of Quality Management Standard for Geological and Mineral Laboratory Testing (DZ/T 0130-2006). The comparison results of uncertainty evaluation further verify the reliability of the method. The test results of samples in field are consistent with those in laboratory, confirming the applicability of the method for anomaly verification and efficiency increasing of geochemical exploration. The method can meet the requirements of rapid batch determination of 20 elements in field geological samples.