The invention relates to a grain sorting device based on an automatic analysis camera for heavy metal content and a method. A material taking device, a material receiving box, a sample detector and anintelligent material separating vehicle are sequentially arranged below a discharge opening of a hopper box, a material taking bin is arranged on the material taking device, a material taking bottomplate with a material taking opening is arranged at the bottom of the material taking device, and the material taking bottom plate is fixedly connected with the hopper box. When the material taking device rotates, the material taking bin is intermittently in communication with the material taking opening of the hopper box and the material taking opening of the material taking bottom plate, and thematerial taking opening of the material taking bottom plate is in communication with the material receiving box and the sample detector. A material equalizing piston is arranged in the lower part ofthe material receiving box, a movable bottom plate is arranged at the bottom of the sample detector, a plurality of automatic analysis cameras for heavy metal content are arranged at one side of the sample detector, and the automatic analysis cameras for heavy metal content are correspondingly connected to a control CPU. The control CPU analyzes and obtains the mean value of heavy metal content and transmits the mean value to an induction receiver of the intelligent material separating vehicle, and at the same time, the CPU is controlled to control the movable bottom plate to open to realize discharging, and the intelligent material separating vehicle distributes grain to designated sorting bins according to the analysis results of the heavy metal content.