NOVELTY - A coordination polymer film material is prepared by coordinating nickel metal ion with L-aspartic acid and 4,4-bipyridine, forming three-dimensional hole material with uniform hole size, coordinating nickel metal and L-aspartic acid of oxygen atom, forming a layer, supporting coordination column of 4,4-bipyridyl with nitrogen atom, and forming a three-dimensional structure.    USE - Coordination polymer film material is used for separating mixed gas e.g. mixed gas of hydrogen and carbon dioxide, mixed gas of hydrogen and methane or mixed gas of hydrogen and nitrogen, and chiral isomer e.g. chiral glycol, chiral amino acid and chiral drug molecules.    ADVANTAGE - The coordination polymer film material has favorable separation.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) preparation of coordination polymer film material, which involves pressing 2-5 layers of 100-400 meshes single layer nickel mesh into nickel sheet under 10-200 MPa, or pressing nickel powder having average particle size of 10-20 mu m on nickel-based micro-filtration film sheet having aperture of less than 1 mu m, porosity factor of 30-40% and thickness of 1-3 mm under 10-200 MPa, and putting nickel-based micro-filtration film sheet or nickel sheet into a beaker, adding deionized water and scouring agent, in mass ratio of 1:0.01-0.1 into the beaker, ultrasonic processing for 10-30 minutes, taking out nickel-based micro-filtration film sheet or nickel sheet, adding deionized water to ultrasonic process for 10-15 minutes, pouring liquid in breaker, repeating ultrasonic treatment for 2-5 times, taking out and then putting into an oven at 80-150 degrees C, drying for 1-5 hour, adding L-aspartic acid, 4,4-bipyridine, water and methanol, in weight ratio of 1:0.1-10:0.1-10:1-100 into the beaker, stirring, pouring the obtained reaction mother liquor into a reactor, horizontally putting the washed nickel-based micro-filtration film sheet or nickel sheet carrier into reaction mother liquor, screwing the reactor cover, then putting reactor in an oven at 100-200 degrees C for in-situ growing for 1-5 days, taking out reactor, and then cooling to room temperature, putting the growing coordination polymer film material into oven at 100-200 degrees C for 5-10 hours, naturally cooling at room temperature, and removing water and methanol guest molecules of film material;    (2) use of coordination polymer film material for separating mixed gas; and    (3) use of coordination polymer film material for separating chiral isomer.