The present invention provides a detection device and a detection method. The detection device comprises a light source module, a receiving module, an image generation module and a judgment module, wherein the light source module is configured to emit light towards a film at a predetermined angle, the receiving module is configured to receive interference light formed by first reflected light reflected by an upper surface of the film and second reflected light reflected by a lower surface of the film, the image generation module is configured to generate an interference fringe image according to the interference light, and the judgment module is configured to judge whether thickness of the film is uniform according to the interference fringe image. The detection device can perform high accuracy detection on uniformity of the thickness of a film, thereby facilitating improving display quality of a display panel.