The invention relates to a self-driven vertical storage tank washing device which comprises a storage tank, a sliding sleeve and a hollow cylinder cam. A guide ball is welded to the inner side of the sliding sleeve. The outer side of the hollow cylinder cam is provided with a guide groove. The guide ball can slide in the guide groove. A misaligned flow divider is installed on the lower side of the hollow cylinder cam. A connecting pipe is installed on the lower side of the misaligned flow divider. Two horizontal telescoping rods are welded to the outer side of the connecting pipe. A spring is installed on the outer side of each horizontal telescoping rod. The springs and the horizontal telescoping rods are coaxial. A hairbrush is installed on the side, close to the inner side of the storage tank, of each horizontal telescoping rod. A fan-shaped spraying head spraying downwards is installed on the lower side of the connecting pipe. According to the self-driven vertical storage tank washing device, by arranging the misaligned flow divider and the spraying head, rotating torque generated by jet flow can be utilized for enabling the hollow cylinder cam to rotate. By arranging the hollow cylinder cam and the sliding sleeve, the hollow cylinder cam can do up and down reciprocating motion along the axis. By arranging the springs and the horizontal telescoping rods, the hairbrushes can make contact with the inner surface of the storage tank all the time, and the application range of the device is enlarged. Moreover, the self-driven vertical storage tank washing device is simple in structure, convenient to operate, economical and practical.