The invention discloses an asymmetric dipyridyl alkene compound and a preparation method and applications thereof. The chemical structure formula of the compound is represented in the description. Thepreparation method has the advantages of simple technology, mild reaction conditions, and high yield. Synthesized 1-(2-amino-3-pyridyl)-2-(4-pyridyl)-ethylene can be used as an organic ligand to carry out self assembly with transition metal ions to form coordination polymer [cadmium(1-(2-amino-3-pyridyl)-2-(4-pyridyl)-ethylene)(5-nitro-1,3-phthalic acid)]n; the structure of the cadmium coordination polymer is stable in water; the coordination polymer can catalyze the photo degradation of an organic dye namely rhodamine B; the organic dye is decomposed to generate CO2 and H2O, which are pollution-free; and the catalyst can be repeatedly used.