Abstract: A heavy metal detector includes a housing composed of a top cover and a base, and a main machine and an electrolysis module arranged in the housing, wherein the main machine includes a main machine circuit, and the main machine circuit includes a main controller, a power supply module, a signal acquisition and processing module, an electrolysis module interface and a signal conversion module. The electrolysis module interface is configured to connect the electrolysis module and the signal acquisition and processing module; the signal acquisition and processing module is configured to receive a characteristic electrical signal output by the electrolysis module, and output a detection result to the main controller; and the main controller displays the detection result on a display module. Multiple electrolysis module interfaces are provided. The base is provided with a plurality of electrolysis module installation ports and stirring devices corresponding to the electrolysis module installation ports.