The utility model relates to a driving device of a movement mechanism in which a roller is used as a walking device, in particular to a roller floating driving device. The roller floating driving device can be adapted to the roller movement mechanism to make various deformation movements. The roller floating driving device comprises a motor (1), a speed reducer (2), a support (5) and a wheel bracket (6), wherein the motor (1) and the speed reducer (2) are placed on the upper portion of the device, and the support (5) and the wheel bracket (6) are placed on the lower portion of the device. The support comprises an upper half part (501) and a lower half part (502), the upper half part and the lower half part are hinged together, and the lower half part is connected with the wheel bracket through a sliding block and a sliding rail. The wheel bracket is provided with a drive shaft (12) and a back gear shaft (7), and the drive shaft and the back gear shaft are arranged on the wheel bracket in the mode that the drive shaft and the back gear shaft can rotate around the drive shaft and the back gear shaft themselves. An output shaft of the speed reducer is connected with the upper end of a cardan shaft (3) through a half coupler, and the lower end of the cardan shaft is connected with the upper end of the drive shaft through a half coupler. A drive gear (11) is arranged at the lower end of the drive shaft, and a back gear (8) is arranged at the lower end of the back gear shaft.