A testing device and a testing method for an optical film are disclosed. The testing device includes a carrier having a cavity, wherein the cavity is an enclosed space; a test condition providing module disposed in the enclosed space; wherein the optical film is disposed in the enclosed space and the test condition providing module is configured for providing a test condition simulating a real environment in a liquid crystal display module for the optical film. The testing device for an optical film is configured for testing the optical film to be tested.