Method, device and system for detecting heavy metals in soil

An embodiment of the invention provides a method, a device and a system for detecting heavy metals in soil and belongs to the field of soil detection. The method comprises steps as follows: under a preset detection condition, the device for detecting the heavy metals in the soil acquires the second characteristic X-ray spectrum of to-be-detected soil, and the second characteristic X-ray spectrum comprises the wavelength and the intensity corresponding to the heavy metals in the to-be-detected soil; the wavelength and the intensity in the second characteristic X-ray spectrum are compared with those in a first characteristic X-ray spectrum, and types of the heavy metals corresponding to the wavelength, identical to the wavelength in the second characteristic X-ray spectrum, in the first characteristic X-ray spectrumare used as types of the heavy metals in the to-be-detected soil; the intensities, corresponding to same types of heavy metals, in the first and second characteristic X-ray spectrums are compared, the content of the heavy metals in the to-be-detected soil is obtained according to the corresponding relation between the intensity and the known content of the heavy metals in the first characteristic X-ray spectrum, and the accuracy of soil heavy metal detection results is significantly improved.