The present invention provides a driving component, a photosensitive drum and a process cartridge. The driving component comprises a gear having one fixed end and a regulating component having a rotational driving force receiver outside the other end projecting from the gear. The regulating component is provided within the gear by being moved reciprocally and translationally along the gear's longitudinal direction and a first direction perpendicular to the longitudinal direction relative to the gear. A spring support part and a longitudinal position limit part are provided between the regulating component and the gear. The rotational driving force receiver is provided inside the regulating component by rotating around its own axis. Compared to the existing technology, the process cartridge using this driving component has a smooth engagement with a printer, reliable performance and stable work.