We quantitatively analyze the content of the element Ni in the Chinese national standard soil samples by the method of X-ray fluorescence spectroscopy using XLt793 metal analyzer in ambient environment of the laboratory. The direct calibration curve of Ni is measured by studying the characteristics of X-ray fluorescence of Ni in the optimal experimental conditions. The experimental results demonstrate that the relation between concentration \[mass fraction (50~1000)×10-6\] of Ni element and the intensity of the characteristic spectrum is well linear, and the relative standard deviation (RSD) of intensity measurement from the standard value is 8.60%. Using the soil samples of the same type the relative deviation of element analysis of concentration measurement from the standard value is 4.43%. Using calibration curves to analyze the different soil types, the relative deviation between the measured concentration and the standard value is 7.13%.