The invention mainly relates to a material for detecting and separating a metal ion in an aqueous solution and a preparation method of the material. The material is as shown in the formula I, and a compound A as a recognition receptor in the formula I is connected to the surface of a cellulose carrier C via an active group B in a covalent mode. The material can be applied to the detection and separation of the metal ion in an environment. The fiber separation material is stable in physical and chemical property, and has the advantages of wide application range, high removing capacity, high selectivity, renewability and the like.