A detection apparatus, a detection method and a detection system are provided. The detection apparatus includes: a light source module used to provide illumination for color filters; an image obtaining module used to obtain image data of the color filters; a light adjusting module disposed at a light-emitting side of the light source module and used to adjust a light direction of the light source module to make the light direction coincide with an orientation of the pixel units on a first direction or a second direction perpendicular to the first direction; a data processing module connected to the image obtaining module and used to perform a processing on the image data and judge whether there is an unqualified pixel unit in the pixel units as per a result of the processing. The light direction is adjustable to coincide with the orientation of pixel units.