Drum assembly, process cartridge and image forming apparatus

The embodiment of the invention provides a drum assembly, a processing box and an image forming device, and relates to the technical field of imaging. The drum assembly comprises a shell, a photosensitive drum, a light guide column and a light guide connecting piece. When the drum assembly is installed on the device body, the distance between the position corresponding to the projection of the second end of the light guide connecting piece on the side plate and the installation position of the driving device is larger than the distance between the position corresponding to the projection of the first end on the side plate and the installation position of the driving device. Therefore, the distance between the mounting position of the discharge lamp and the mounting position of the driving device of the photosensitive drum can be increased, interference between the discharge lamp and the driving device of the photosensitive drum is avoided, and the operation stability of the driving device of the photosensitiv