The main principle of the latex method for testing new coronavirus is the binding reaction between antibody and antigen. Latex method is also called colloidal gold method, specifically colloidal gold flow measurement immunochromatographic method, refers to the detection method of colloidal gold as a tracer marker, is currently approved by the State Drug Administration of the new coronavirus antibody test method in one. Take the current common IgG antibody detection colloidal gold method as an example, its kit can be disassembled into 5 parts: sample pad, binding pad, detection line, accusation line and absorbent pad. Among them, the sample pad is the part for dropping the sample and diluting and, under the action of absorbent paper, the added sample will be passed from left to right. When the sample is passed, it will bind to the colloidal gold and viral spiking protein of the binding pad, the mouse anti-human IgG antibody on the detection line, and the sheep anti-mouse IgG antibody on the accusation line, respectively, which will result in different color changes, and then determine whether there is a viral infection or not. However, since the State Drug Administration has approved more than 20 new coronavirus antibody test kits, there are certain differences in the use and principle of different kits, and the specifications should be based on the product manual.