Light trigger color changing film is a kind of new functional materials used in various fields. Polyethylene was used as masterbatch and green phosphor as color agent in the experiment. The film was prepared by blow molding. The mechanical properties, optical properties and the color changing properties of the film were tested. The result showed that the best temperature of polyethylene melting is 188 ℃in IVarea; when the ratio of green phosphor and polyethylene is 1%, color changing properties is the best and color changing sensitivity is the highest.