Lead ion spot detecting test paper and preparation method of lead ion spot detecting test paper

The invention discloses lead ion spot detecting test paper and a preparation method of the lead ion spot detecting test paper. The lead ion spot detecting test paper comprises a cross-linking polymeric membrane with a lead iron cavity network structure; and the test paper can perform specificity identification on lead irons and is high in detection sensitivity. In one embodiment of the lead ion spot detecting test paper, the spot detecting technology is combined with the photonic crystal technology, so that the prepared lead ion spot detecting test paper not only has high specificity identification ability and high optional absorption ability to lead irons, but also can identify and reflect the concentration change through color change; and the lead ion spot detecting test paper is simple, convenient, rapid, sensitive to act, high in precision, low in price, easy to preserve and the like, and is particularly suitable for on-site detection and substrate testing laboratories.