Laser induced breakdown spectroscopy (LIBS) combined with the standard addition method is used to detect the Cr concentration in soil. With the Cr 425.435 nm line as the characteristic line and Fe as the internal standard element, the Cr calibration curve is established. Based on the fact that when the Cr mass fraction is below 250×10-6, the spectral intensity of characteristic line has a linear relationship with its mass fraction, the limit of detection is 9.69×10-6 and the detection range of the standard addition method is obtained. The standard addition methods with one and five extrapolated points are studied. For five-point standard addition method, the relative error of test results of Cr in soil is less than 7%. For one-point standard addition method, the relative error is less than 10%. Detect one soil sample by one-point standard addition method for five times, the relative standard deviation (RSD) of the test results is 4.66%, which is relatively stable. Experimental results show that LIBS combined with standard addition method can perform well in quantitative detection of Cr in soil.