The invention discloses an automatic stool detector, comprising: a sample rack (1), a buffer area (2), an emergency position (3), a scanning part (4), a sample tray (5), a mechanical arm (6), a stirring Mechanism (7), sample loading unit (8), colloidal gold transfer mechanism (9), colloidal gold stack (10), microscope inspection unit (11), immunophotography unit (12), reaction chamber (13), colloidal gold waste material recovery (14). A mechanical arm is arranged above the sample tray. The robotic arm grabs the sample bottle from the sample rack to the station on the sample tray. The stirring mechanism stirs the material in the sample vial. The sample adding part adds the reagent into the sample bottle. The microscope inspection department conducts a microscope inspection on the materials in the sample bottle. The colloidal gold transfer mechanism extracts the colloidal gold from the colloidal gold stack (10), adds a sample, and then transfers the colloidal gold added with the sample to the reaction chamber (13). Immunophotographic department takes pictures to identify positive and negative. The colloidal gold waste recycling mechanism (14) recycles the colloidal gold.